Friday, 17 October 2014

CRYSTAL BALL AND MAGIC WAND:The Dangerous Promise of Big Data

by Dirk Helbing

This is third in  a  series of blog posts that form chapters of my forthcoming book Digital Society. Last week's chapter was titled:  COMPLEXITY TIME BOMB: When systems get out of control

Data sets bigger than the largest library

The idea that we could solve the problems in the world, if we just had enough data about them, is intriguing. In fact, we are now entering an era of "Big Data" – masses of information, mostly in digital form, about all aspects of our lives, institutions and cultures. It will probably not be long before each newborn baby will have its genome sequenced at birth. Every purchase we make on the Internet releases data about our location, preferences, and finances that will be stored somewhere and quite possibly used without our consent. Cell phones disclose where we are, and private messages and conversations are not really private at all. Books are being digitized beyond the advent of printing, and are available in immense, searchable databases of words that are now being mined in "culturomics" studies that put history, society, art and cultural trends under the lens. Aggregated data can be used to reveal unexpected facts, such as flu epidemics being inferred from Google searches.

This avalanche of data is ever increasing: with the introduction of technologies such as Google Glass, people will have the option of documenting and archiving almost every aspect of their lives. Big Data such as credit-card transactions, communication and mobility data, public news, Google Earth imagery, comments and blogs, are creating an increasingly accurate digital picture of our physical and social world, including all its social and economic activities.

"Big Data" will change our world. The term, coined more than 15 years ago, means data sets so big that one can no longer cope with them with standard computational methods. To benefit from Big Data, we must learn to "drill" and "refine" data, i.e. to transform them into useful information and knowledge. The global data volume doubles every 12 months. Therefore, each year we produce as much data as in all previous years together.

These tremendous amounts of data relate to four important technological innovations: the Internet, which enables our global communication, the World Wide Web (WWW), a network of globally accessible websites that evolved after the invention of hypertext protocol (HTTP), the emergence of Social Media such as Facebook, Google+, Whatsup, or Twitter, which have created social communication networks, and the emergence of the "Internet of Things" (IoT), which allows sensors, smartphones, gadgets, and machines ("things") to connect to the Internet. Note that there are already more things connected to the Internet than humans.

Meanwhile, the data sets collected by companies such as ebay, Walmart or Facebook, reach the size of petabytes (1 million billion bytes)one hundred times the information content of the largest library in the world: the U.S. Library of Congress. The mining of Big Data opens up entirely new possibilities for the optimization of processes, the identification of interdependencies, and the support of decisions. However, Big Data also comes with new challenges, which are often characterized by four criteria: volume (the file sizes and number of records are huge), velocity (the data evaluation has often to be done in real-time), variety (the data are often very heterogeneous and unstructured), and veracity (the data are probably incomplete, not representative, and contain errors).

Gold rush for the 21st century's oil

When the social media portal WhatsApp with its 450 million users was recently sold to Facebook for $19 billion – almost half a billion dollars was made per employee. There’s no doubt that Big Data create tremendous business opportunities – not just because of its value for, say, marketing, but because the information itself is becoming monetarized.

Technology gurus preach that Big Data is becoming the new oil of the 21st century: a commodity that can be tapped for profit. With the virtual currency BitCoin temporarily becoming more valuable than gold, one can even literally say that data can be turned into value to an extent we only knew from fairy tales. Even though many sets of Big Data are proprietary, the consultancy company McKinsey recently estimated the potential value of Open Data alone to be 3 to 5 trillion dollars per year. If the worth of this publicly available information were to be evenly apportioned among the public itself, it would bring $500 to each person in the world.

The potential of Big Data spans all areas of social activity: from natural language processing to financial asset management, or to a smart management of cities that better balances energy consumption and production. It could enable better protection of our environment, risk detection and reduction, and the discovery of opportunities that would otherwise be missed. And it could make it possible to tailor medicine to patients, thereby increasing drug effectiveness, accelerating drug discovery and reducing side effects.

Big Data applications are now spreading very rapidly. They enable personalized services and products, open up entirely new possibilities to optimize production and distribution processes or services, allow us to run "smart cities," and reveal unexpected interconnections between our activities. Big Data also hold great potential for fostering evidence-based decision-making, particularly in big business and politics. Where is all of this leading us?

In this post, I explain what Big Data can and cannot do. In particular, I will show that it will never be enough on its own to avoid crises and catastrophes, or to solve all societal problems. Indeed, the suggestion sometimes heard – that Big Data is the key to the future – can be misleading in pretty dangerous ways. Most obviously, it could precipitate a descent into an authoritarian surveillance state where there is very little personal liberty or autonomy, and where no one can have any more secrets. But even if that were not to happen, Big Data could create a false sense that we can control our own destiny, if only we have enough data. Information is potentially useful, but it can only release its potential if it is coupled to a sound understanding of how complex social systems work.

Big Data fueling super-governments

The development of human civilization has depended on the establishment of mechanisms that promote cooperation and social order. One of these is based on the idea that everything we do is seen and judged by God. Bad deeds will be punished, while good ones will be rewarded. The age of information has inspired the dream that we might be able to know and control everything ourselves: to acquire God-like omniscience and omnipotence. There are now hopes and fears that such power lies within the reach of huge IT companies such as Google or Facebook and clandestine secret services such as the CIA or NSA. CIA Chief Technology Officer Ira "Gus" Hunt[2] has explained how easy it is for such institutions to gather a great deal of information about each of us:
"You're already a walking sensor platform… You are aware of the fact that somebody can know where you are at all times because you carry a mobile device, even if that mobile device is turned off. You know this, I hope? Yes? Well, you should… Since you can't connect dots you don't have, it drives us into a mode of, we fundamentally try to collect everything and hang on to it forever… It is really very nearly within our grasp to be able to compute on all human generated information." 
Could such a massive data-collection process be good for the world, helping to eliminate terrorism and crime? Or should we fear that the use of this information will undermine human rights and the basis of democratic societies and free economies? In this chapter, I explore the possibilities and limits of such an approach, for better or worse.

Imagine you are the president of a country, intending to ensure the welfare of all its people. What would you do? You might well wish to prevent wars and financial crises, economic recessions, crime, terror, and the spread of diseases. You may want people to be rich, happy, and healthy. You would like to avoid unhealthy drug consumption, corruption, and perhaps traffic jams as well. You would like to ensure a safe, reliable supply of food, water, and energy, and to keep the environment in good shape. In sum, you would like to create a prosperous, sustainable and resilient society.

What would it take to achieve all this? You would certainly have to take the right decisions and avoid those that would have harmful, unintended side effects. So you should know about alternatives for impending decisions, along with their opportunities and risks. For your country to thrive, you would have to avoid ideological, instinctive or traditional decisions in favor of evidence-based decisions. To have the evidence needed to inform this decision-making, you would need a lot of data about all quantifiable aspects of society, and excellent data analysts to interpret it. You might well decide to collect all the data you can get, just in case it might turn out to be useful one day to counter threats and crises, or to exploit opportunities that might arise.

Previously, rulers and governments were not in this position: they generally lacked the quality or quantity of data needed to take well-informed decisions. But that is now changing. Over the past several decades, the processing power of computers has exploded, roughly doubling every 18 months. The capacity for data storage is growing even faster. The amount of data is doubling every year. With the now emerging "Internet of Things," cell phones, computers and factories will be connected to the most mundane devices – coffee machines, fridges, shoes and clothes – creating an overwhelming stream of information that feeds an ocean of "Big Data."

Humans governed by computers?

The more that data is generated, stored and interpreted, the easier is it to find out about each individual’s behavior. Everyone's computer and everyone's device-encoded behavior (such as the record of our movements produced by the cell phones we carry) leaves a unique fingerprint, such that it is possible to know our interests, our thinking, our passions, and our feelings. Some companies analyze "consumer genes" to offer personalized products and services. They have already collected up to 3,000 personal data from almost a billion people in the world: names, contact data, incomes, consumer habits, health information, and more. This is pretty much everyone with a certain level of income and Internet connectivity.

Would it be beneficial if a well-intentioned government had access to all this data? It could help politicians and administrations to take better informed decisions: to reduce terrorism and crime, say, and to use energy more efficiently, protect our environment, improve traffic flows, avoid financial meltdowns, mitigate recessions, enhance our health system and education, and provide better fitting services to citizens.

Moreover, could a government use the information not only to understand but also to predict our behavior, and map out the course of our society? Could it optimize our social systems and take the best decisions for everyone?

In the past, we have used supercomputers for almost everything except understanding our economy, society, and politics. Every new car or airplane is designed, simulated, and tested on a computer. Increasingly, so are new drugs. Thus, why shouldn't we use computers to understand and guide our economy and society too? In fact, we are slowly moving towards that very situation. As a minor (yet revealing) example, since their early days computers have been used for traffic control. Today’s economic production and the management of supply chains would not be conceivable without computer control as well, and large airplanes are now controlled by a majority decision among several computers. Computers can already beat the best chess players, and about 70 percent of financial transactions are executed by trading computers in the meantime. IBM's Watson computer has started to take care of some customer hotlines, and computer-driven Google cars will soon move around without a driver, perhaps picking up the goods we ordered on the Web without us being present. In all these cases, computers already do a better job than humans. Why shouldn't they eventually make better policemen, administrators, lawyers, and politicians?

It no longer seems unreasonable, then, to imagine a gigantic computer program that could simulate the actions and interactions of all the humans in the world, perhaps even equipping these billions of agents with cognitive abilities and intelligence. If we fed these agents with our own personal data, would they behave as we do? In other words, would it be possible to create a virtual mirror world? And would machine learning eventually be able to build the computer agents so similar to us that they would take decisions undistinguishable from ours? Attempts to construct or at least envisage such a scheme are already underway. If they were realized, would they represent a kind of Crystal Ball with which we could predict the future of society?

The prospect might sound unnerving to some, but in principle the potential benefits aren’t hard to see. There are many huge problems that such a predictive capability might help to solve. The financial crisis has created global losses of at least 20 trillion US dollars. Crime and corruption consume about 2-5% of the gross domestic product (GDP) of all nations on earth – about 2 trillion US dollars each year. The lost output of the US economy as a result of the 9/11 terror attacks is estimated to be of the order of 90 billion dollars. A major influenza pandemic infecting 1% of the world’s population would cause losses of 1-2 trillion dollars per year. Cybercrime costs Europe alone 750 billion Euros a year. The negative economic impact of traffic congestion amounts to 7-8 billion British Pounds in the United Kingdom alone.

If a computer simulation of the entire global socio-economic system could produce just a 1 percent improvement in dealing with these problems, the benefits to society would be immense. And in fact, if experiences with managing smaller complex social systems this way are any guide, an improvement of 10-30 percent seems conceivable. Overall this would amount to savings of more than 1 trillion dollars annually. Even if we had to invest billions in creating such a system, the benefits could exceed the investments hundred-fold. Even if the success rates were significantly smaller, this would represent a substantial gain. It would be hard to see how any responsible politician could decline to support such an investment.

But would such a system work as one might hope? Is Big Data all a government needs to get our world under control?

Crystal Ball and Magic Wand

Recent studies using smartphone data and GPS traces suggest that more than 90 percent of the mobility of people – where they will be at a certain time – can be forecast, because of its repetitive nature. If other aspects of our behavior show the same degree of predictability, it’s not hard to imagine that the trajectory of society can indeed be mapped out in advance, with all that this entails for successful social planning. While some people might not like this prospect at all, many would perhaps appreciate a predictable life.

How far does this idea extend? If we have enough data about every aspect of life, could we become omniscient about the future? In order to achieve that, we would need to be able to manipulate people’s choices using the information provided to them. Personalized Internet searches, systems such as Google Now, and personalized advertising are already going in this direction.But given the overwhelming amount of data available, it needs to be filtered before to be useful. 

Such filtering will inevitably be done in the interests of those who do the filtering. For example, companies want potential customers to see their ads and buy their products. The better people’s characteristics are known, the easier it becomes to manipulate their choices. A recent, controversial Facebook experiment with 600 million users showed that it is possible to manipulate people’s feelings and mood. Therefore, it’s not hard to imagine that omniscience might indeed imply omnipotence: those who know everything could control everything. Let's call the hypothetical tool creating such power a "Magic Wand".

Assuming that we had a Magic Wand, could we take the right decisions for our society, or even for every individual? Many people might say that forecasting societal trends is different from forecasting the weather: the weather does not care about the forecast, but people will respond to it, and this will defeat the prophecy. That seems to imply that successful forecasting of societal developments would require that people don't know about the forecasts, while governments do. This again suggests that one would need a secretly operating authority advising the government about the right decisions, and that it would use the Magic Wand according to the evidence provided by the data-collecting Crystal Ball. Could such a scheme work?

A New World Order based on information? 

Our "wise king" or "benevolent dictator" would probably see the Crystal Ball and the Magic Wand as perfect tools to create social order. Singapore is sometimes seen as an approximation of such a system. The country has indeed been enormously successful in the past decades, but despite great advances and fast economic growth, people's satisfaction has decreased. Why?

A wise king would certainly sometimes have to interfere with our individual freedoms, if we would otherwise take decisions that would create more damage for the economy and society than benefits. This might end up in a situation where we would always have to execute what the government wants us to do, pretty much as if they were commands from God. If we were manipulated in our decision-making, this might even happen without our knowledge. Although the wise king would not be able to fulfill our wishes all the time, on average he might create better outcomes for everyone as long as do as we are told. Sure, this sounds dystopian, but let us nevertheless pursue the concept for a while to see whether it is feasible in principle. If we obediently followed the dictates of the wise king, could this improve the state of the world and turn it into a perfectly working clockwork?

Why top-down control is destined to fail

In short, it would not work. This kind of top-down management, even if guided by comprehensive information, is destined to fail. This book is, therefore, concerned with elaborating alternative and better ways of using data, which are compatible with constitutional rights and cultural values such as privacy. But let us first figure out what are the reasons why a well-working Crystal Ball and Magic Wand can't exist.

One of the problems is statistical in nature. To distinguish “good” from “bad” behavior, we need criteria that clearly separate the two. In general, however, reliable criteria of this sort don’t exist. We face the problems of false positive classifications (false alarms, so-called type I errors) and false negatives (type II errors, where the alarm is not triggered when it should be).

For example, imagine a population of 500 million people, among which there are 500 terrorists. Let’s assume that we can identify terrorists with an extremely impressive 99 percent accuracy. Then there are 1 percent false negatives (type II error), which means that 5 terrorists are not detected, while 495 will be discovered. It has been revealed that about 50 terror acts were prevented over the past 12 years or so, while a few, such as the one during the Boston marathon, were not prevented even though the terrorists were listed in some databases of suspects (in other words, they turned out to be false negatives).

How many false positives (false alarms) would the above numbers create? If the type I error is just 1 out of 10,000, there will be 50,000 wrong suspects, while if it is 1 in one thousand then there will be 500,000 wrong suspects. If it is 1 percent (which is entirely plausible), there will be 5 million false suspects! It has been reported that there are indeed between 1 and 8 million people on lists of suspects in the USA. If these figures are correct, this would mean that for every genuine terrorist, up to 10,000 innocent citizens would be wrongly categorized as potential terrorists. Since the 9/11 attacks, about 40,000 suspects have had to undergo special questioning and screening procedures at international airports, even though in 99 percent of these cases it was concluded that the suspects were innocent. And yet the effort needed to reach even this level of accuracy is considerable and costly: according to media reports, it involved around a million people who had a National Security Agency (NSA) clearance on the level of Edward Snowden. 

So, large-scale surveillance is not an effective means of fighting terrorism. This conclusion has, in fact, been reached by several independent empirical studies. Applying surveillance to the whole population is not sensible, for the same reasons why it is not generally useful to apply prevention-oriented medical tests or medical treatments to the entire population: since such mass screenings imply large numbers of false positives, millions of people might be wrongly treated, often with negative side effects on their health. Thus, for most diseases, patients should be tested only if they show worrying symptoms.

Besides these errors of first and second kind, one may face errors of third kind, namely inappropriate models for separating "good" from "bad" cases. For example, unsuitable risk models have been identified as one reason for the recent financial and economic crisis. The risks of many financial products turned out to be wrongly rated, creating immense losses. Adair Turner, head of the UK Financial Service Authority, has said that there is
“a strong belief ... that bad or rather over-simplistic and overconfident economics helped create the crisis. There was a dominant conventional wisdom that markets were always rational and self-equilibrating, that market completion by itself could ensure economic efficiency and stability, and that financial innovation and increased trading activity were therefore axiomatically beneficial.”

Limitations of the Crystal Ball

One might think that errors of first, second, and third kind could be overcome if only we had enough data. But is this true? There are a number of fundamental scientific factors that will impair the Crystal Ball’s functioning (see Information Box 1). The problem known as "Laplace's Demon" reflects on the history-dependence of future developments, and our inability to ever measure all the past information needed to predict the future, even if the world changed according to deterministic rules (that is, if there were no randomness). This is why we are still influenced by cultural inventions, ideas, and social norms that are hundreds or thousands of years old. 

Furthermore, turbulence and chaos are well-known properties of many complex dynamical systems. These factors imply that even the slightest change in the system at a certain point in time may fundamentally change the outcome over a sufficiently long period of time. The phenomenon, also named the "butterfly effect," is well-known to impose limits on the time horizon of weather forecasts.[3] In social systems as in the weather system, this extreme sensitivity to small but unpredictable disturbances arises from the complexity of the system: the existence of many inter dependencies between the component parts. 

Furthermore, we can determine the parameters of our models only with a finite accuracy. However, even small changes in these parameters may fundamentally change the outcome of the model. There is also a problem of ambiguity: the same information may have several different meanings depending on the respective context, and the particular interpretation we choose may influence the future course of the system. Beyond this, we also know that certain statements are fundamentally “undecidable” in the sense that there are questions that cannot be answered with formal logic. Lastly, too much information may reduce the quality of predictions because of over-fitting, spurious correlations, and herding effects. The Information Box at the end of this chapter elaborate these points in more detail.So one can say that Big Data is not the universal tool that it is often claimed to be.[4] Any attempt to predict the future will be limited to probabilistic and mostly short-term forecasts. It is therefore dangerous to suggest that a Crystal Ball could be built that would reliably predict the future. 

Limitations of the Magic Wand

If the Crystal Ball is cloudy, it doesn’t augur well for the Magic Wand that would depend on it. In fact, top-down control is still very ineffective, as the abundance of problems in our world shows. To control complex systems, i.e. to force them to behave in certain ways, we often do not understand them well enough and lack effective means. Therefore, in many cases attempting to control a complex dynamical system in a top down way undermines its functionality. The result is often a broken system, for example, an accident or crisis. 

An example of the failure of top-down control is the fact that even the most sophisticated technological control mechanisms for airplane flight safety increased it less efficiently than introducing a non-hierarchical culture of collaboration in the cockpit, when co-pilots were encouraged to question the decisions and actions of the pilot. In another example, the official report on the Fukushima nuclear disaster in Japan stresses that it was not primarily the earthquake and tsunami that were responsible for the nuclear meltdowns, but 

“our reflexive obedience; our reluctance to question authority; our devotion to ‘sticking with the program’; our groupism.”

In other words, the problem was too much top-down control. Attempts to control complex systems in a top-down way are also very expensive, and we find it increasingly hard to pay for them: most industrialized countries already have debt levels of at least 100 or 200 percent of their gross domestic product. But do we have any alternatives? In fact, the next chapters of this book will elaborate one.

Complexity is the greatest challenge, but also the greatest opportunity

There are further reasons why the concept of a "super-government", "wise king" or "benevolent dictator" can’t really work. These are related to the complexity of socio-economic systems. There are at least four kinds of complexity that matter: dynamic complexity, structural complexity, functional complexity and algorithmic complexity. The problem of complex dynamics has been addressed in the previous chapter. Here, I will focus on implications of structural, functional and algorithmic complexity. In fact, with a centralized super-computing approach we can only solve those optimization problems, which have sufficiently low algorithmic complexity. However, many problems are "NP-hard," i.e. so computationally demanding that they cannot be handled in real-time even by super-computing. This problem is particularly acute in systems that are characterized by a large variability. In such cases, top-down control cannot reach optimal results. In the next chapter, I will illustrate this by the example of traffic light control.

Given the quick increase in computing power, couldn’t we overcome this challenge in the future? The surprising answer is “no.” While the processing power doubles every 18 months (blue curve in the illustration above), the amount of data doubles every year (green curve above). This implies that we are heading from a situation in which we did not have enough data to take good decisions, to a situation where we can take evidence-based decisions. However, despite the rising processing power, we will be able to process a decreasing share of all the data existing in the world. Moreover, the lack of processing power will be quickly increasing. So we are moving to a situation where we can shed light on everything with a spotlight, but many things will remain unseen in the dark. This creates a new kind of problem: paying too much attention to some problems, while neglecting others. In fact, governments didn't see the financial crisis coming, they didn't see the Arab Spring coming, they didn't see the crisis in the Ukraine coming, and they didn't see the Islamic State (IS) fighters in Iraq coming. Thus, keeping a well-balanced overview of everything will become progressively more difficult. Instead, politics will be increasingly driven by problems that suddenly happen to gain public attention, i.e. made in a reactive rather than anticipatory way.

But let’s now have a look at the question of how the world is expected to change depending on its complexity. The possibility to network the components of our world creates ever more options. We have, in fact, a combinatorial number of possibilities to produce new systems and functionalities. If we have two kinds of objects, we can combine them to produce a third one. These three kinds of objects allow us to create six ones, and those already 720. This is mathematically reflected by a factorial function, which grows much faster than exponentially (see the red curve above). For example, we will soon have more devices communicating with the Internet than people. In about 10 years from now, 150 billion (!) things will be part of the Internet, forming the "Internet of Things." Thus, even if we realize just every thousandth or millionth of all combinatorial possibilities, the factorial curve will eventually overtake the exponential curves representing data volumes and computational power. It has probably overtaken both curves already some time ago.

In other words, attempts to optimize systems in a top-down way will become less and less effective – and cannot be done in real time. Paradoxically, as economic diversification and cultural evolution progress, a "big government", "super-government" or "benevolent dictator" would increasingly struggle to take good decisions, as it becomes more difficult to satisfy the diverse local expectations and demands. This means that centralized governance and top-down control are destined to fail. Given the situation in Afghanistan and Iraq, Syria, Ukraine, and the states experiencing the Arab Spring, given the financial, economic and public debt crisis, and given the quick spreading of the Ebola disease in Africa, have we perhaps lost control already? Are we fighting a hopeless battle against complexity?

Simplifying our world by homogenization and standardization would not fix the problem, as I will elaborate in the chapter on the Innovation Accelerator. It would undermine cultural evolution and innovation, thereby causing a failure to adjust to our ever-changing world. Thus, do we have alternatives? Actually, yes: rather than fighting the properties of complex systems, we can use them for us, if we learn to understand their nature. The fact that the complexity of our world has surpassed our capacity to grasp it, even with all the computers and information systems assisting us, does not mean that our world must end in chaos. While our current system is based on administration, planning, and optimization, our future world will be built on evolutionary principles and collective intelligence, i.e. intelligence surpassing that of the brightest people and best expert systems.

How to get there? 

In the next chapters, I will show how the choice of suitable local interaction mechanisms can, in fact, create desirable outcomes. Information and communication systems will enable us to let things happen in a favorable way. This is the path we should take, because we don't have better alternatives. The proposed approach will create more efficient socio-economic institutions and new opportunities for everyone: politics, business, science, and citizens alike. As a positive side effect, our society will become more resilient to the future challenges and shocks that we will surely face.


"Big Data" has great potential, in particular for better, evidence-based decision-making. But it is not a universal solution, as it is often suggested. In particular, data-driven approaches are notoriously bad at predicting systemic shifts, where the entire way of organizing or doing things change. Moreover, like any technology, Big Data can be seriously misused, posing a "dual use problem" (see the Information Box 2 below). Without suitable precautions – for example, the use of "data safes," decentralization, encryption, the logging of large-scale data-mining activities, the limitation of large processing volumes to qualified and responsible users, the accountability of Big Data users for damage created by them, and large fines in cases of damage, misuse, or discrimination – mining Big Data may create massive problems (intentionally or not). It is, therefore, crucial to design socio-technical systems in ways that promote their ethical use.

INFORMATION BOX 1: Limitations to Building a Crystal Ball

Sensitivity - When all the data in the world can't help

How close can computer-modeled behavior ever come to real human social behavior? To specify the parameters and starting conditions of a computer model, these are varied by calibration procedures until the difference between measurement data and model predictions becomes as small as possible. However, the best fitting model parameters are usually not the correct parameters. These parameters are typically within a certain "confidence interval." But if the parameters are randomly picked from the confidence interval, the model predictions may vary a lot. This problem is known as sensitivity.

Turbulence and chaos

Two further problems of somewhat similar nature are "chaos" and "turbulence." Rapid flows of gases or liquids produce swirly patterns – the characteristic forms of turbulence. In chaotically behaving systems, too, the motion becomes unpredictable after a certain time period. Even though the way a "deterministically chaotic" system evolves can be precisely stated in mathematical terms, without random elements, the slightest change in the starting conditions can eventually cause a completely different global state of the system. In such a case, no matter how accurately we measure the initial conditions of the system, we will effectively not be able to predict the later behavior.


Information can have different meanings. In many cases, the correct interpretation can be found only with some additional piece of information: the context. This contextualization is often difficult and not always available when needed. Different pieces of information can also be inconsistent, without any means of resolving the conflict.A typical problem in "data mining" challenges is that data might be plentiful, but inconsistent, incomplete, and not even representative. Moreover, a lot of it might be wrong, because of measurement errors, misinterpretations or application of wrong procedures, or manipulation.

Laplace's Demon and measurement problems

Laplace's Demon is a hypothetical being who could calculate all future states of the world, if he knew the exact positions and speeds of all particles and the physical laws governing their motion and interactions. Laplace's Demon cannot exist in reality, not least because of the fundamental limitation that measurements to determine all particle speeds would be impossible due to the restriction of special relativity: all velocities must be less than the speed of light. This would prevent one from gathering all the necessary data.
Information overload
Having a lot of data does not necessarily mean that we'll see the world more accurately. A typical problem is that of "over-fitting," where a model characterized by many parameters is fitted to the fine details of a data set in ways that are actually not meaningful. In such a case, a model with less parameters might provide better predictions. Spurious correlations are a somewhat similar problem: we tend to see patterns where they actually don't exist (see for some examples).Note that we are currently moving from a situation where we had too little data about the world to a situation where we have too much. It’s like moving from darkness, where we can't see enough, to a world flooded with light, in which we are blinded. We will need "digital sunglasses": information filters that will extract the relevant information for us. But as the gap between the data that exists and the data we can analyze increases, it might become harder to pay attention to those things that really matter. Although computer processing power doubles every 18 months, we will be able to process an ever decreasing fraction of all the data we possess, because the data storage capacity doubles every year. In other words, there will be increasing volumes of data that will never be touched.
When people feel insecure, they tend to follow decisions and actions of others. This produces undesirable herding effects. The economics Nobel laureates George Akerlof (*1940) and Robert Shiller (*1946) have called this behaviour "animal spirits," but in fact the idea of herding in economics goes back at least to the French mathematician Louis Bachelier (1870-1946). Bubbles and crashes in stock markets are examples of where herding can lead.
Randomness and innovation
Randomness is a ubiquitous feature of socio-economic systems. However, even though we would often like to reduce the risks it generates, we would be unwise to try to eliminate randomness completely. It is an important driver of creativity and innovation; predictability excludes positive surprises and cultural evolution. We will see later that some important and useful social mechanisms can only evolve in the presence of randomness. Although newly emerging behaviors are often costly in the beginning, when they are in a minority position, the random coincidence or accumulation of such behaviors in the same neighborhood can be very beneficial, and such behavior may then eventually succeed and spread.

INFORMATION BOX 2: Side effects of massive data collection

Like any technology, Big Data has not only great potential but also harmful side effects. Not all Big Data applications come with these problems, but they are not uncommon. What we need to identify, are those problems that can lead to major crises rather than just localized, small-scale defects.


In the past years, cybercrime has increased exponentially, costing Europe alone around 750 million EUR per year. Some of this has resulted from the undermining of security standards (for example those of financial transactions) for the purpose of surveillance. Other common problems are data theft or identity theft, data manipulation, and the fabrication of false evidence. These crimes are often committed by means of “Trojan horses”, computer codes that can steal passwords and PIN codes. Further problems are caused by computer viruses or worms that damage software or data.

Military risks

Because most of our critical infrastructures are now connected with other systems via information and communications networks, they have become pretty vulnerable to cyber attacks. In principle, malicious intruders can manipulate the production of chemicals, energy (including nuclear power stations), and communication and financial networks. Attacks are sometimes possible even if the computers controlling such critical infrastructures are not connected to the Internet. Given our dependence on electricity, information and money flows as well as other goods and services, this makes our societies vulnerable as never before. Coordinated cyber-attacks could be launched within microseconds and bring the functioning of our economy and societies to a halt.

The US government apparently reserves the right to respond to cyberwar with a nuclear counter-strike. We are now seeing a digital arms race for the most powerful information-based surveillance and manipulation technologies. It is doubtful whether governments will be able to prevent serious misuse of such powerful tools. Just imagine, a Crystal Ball or Magic Wand or other powerful digital tools would exist. Then, of course, everyone wanted to use them, including our enemies, and criminals as well. It is obvious that, sooner or later, these powerful tools would get into wrong hands and finally out of control. If we don't take suitable precautions, mining massive data may (intentionally or not) create problems of any scale – including digital weapons of mass destruction. Therefore, international efforts towards confidence-building and digital disarmament are crucial and urgent.

Economic risks

Cybercrime poses obvious risks to the economy, as do illicit access to sensitive business secrets and theft of intellectual property. Loss of customer trust in products can cause sales losses of the order of billions of dollars for some companies. Systems that would not work effectively without a sufficient level of trust include electronic banking, sensitive communication by email, eBusiness, eVoting, and social networking. Yet more than two thirds of all Germans say they do not trust government authorities and Big Data companies any longer to not misuse their personal data. More than 50 percent even feel threatened by the Internet. The success of the digital economy is further threatened by information pollution, for example, spam and undesired ads.
Social and societal risks
To contain "societal diseases" such as terrorism and organized crime, it often seems that surveillance is needed. However, the effectiveness of mass surveillance in improving the level of security is questionable and hotly debated: the evidence is missing or weak. At the same time, mass surveillance erodes the trustful relationship between citizens and the state. The perceived loss of privacy is also likely to promote conformism and to endanger diversity and useful criticism. Independent judgments and decision-making could be undermined. Excessive state control of the behavior of citizens would, therefore, impair our society’s ability to innovate and adapt.
For such reasons, the constitutions of many countries consider it of fundamental importance to protect privacy, informational self-determination, private communication, and the principle of assumed innocence without proof of guilt. These things are also considered to be essential for human dignity, and elementary preconditions for democracies to function well.
However, today the Internet lacks good mechanisms for forgetting, forgiveness, and re-integration. There are also concerns that the increasing use of Big Data could lead to greater discrimination, which in turn could promote increasing fragmentation of our society into subcultures. For example, it is believed that the spreading of social media has promoted the polarization of US society.
Political risks
It is often pointed out that leaking confidential political communication can undermine the success of sensitive negotiations. Moreover, if incumbent governments have better access to Big Data applications than parties in opposition, this could result in unfair competition and non-representative election outcomes. Last but not least, in the hands of extremist political groups or criminals, Big Data could become a dangerous tool for acquiring and exerting power.

[1] Dear Reader,
thank you for your interest in this chapter, which is thought to stimulate debate.
What you are seeing here is work in progress, a chapter of a book on the emerging Digital Society
I am currently writing. My plan was to elaborate and polish this further, before I share this with anybody else. However, I often feel that it is more important to share my thoughts with the public now than trying to perfect the book first while keeping my analysis and insights for myself in times requiring new ideas.
So, please apologize if this does not look 100% ready. Updates will follow. Your critical thoughts and constructive feedback are very welcome. You can reach me via dhelbing(AT) or @dirkhelbing at twitter.
I hope these materials can serve as a stepping stone towards mastering the challenges ahead of us and towards developing an open and participatory information infrastructure for the Digital Society of the 21st century that would enable everyone to take better informed decisions and more effective actions.
I believe that our society is heading towards a tipping point, and that this creates the opportunity for a better future.
But it will take many of us to work it out. Let’s do this together!
Thank you very much, I wish you an enjoyable reading,
Dirk Helbing
PS: Special thanks go to the FuturICT community and to Philip Ball.
[3] These prediction limits are not just a matter of getting enough measurement data and having a sufficiently powerful computer – one cannot get beyond a certain precision because of the physical nature of the underlying process.
[4] To convince me of the opposite, in analogy to the "Turing test" checking whether a computer can communicate undistinguishable from a human, one would have to demonstrate that a computer system passes the "Helbing test," i.e. finds all fundamental laws of physics discovered by scientists so far, just by mining the experimental data accumulated over time.

Friday, 10 October 2014

COMPLEXITY TIME BOMB: When systems get out of control

 by Dirk Helbing

                                                                                                                                                                                Photo: RenateWernli

This is second in  a  series of blog posts that form chapters of my forthcoming book Digital Society. Last week's chapter was titled:  GENIE OUT OF THE BOTTLE: The digital revolution on its way.

Financial crises, terrorism, conflict, crime: it turns out, the conventional ‘medicines’ to tackle global problems are often inefficient or even counter-productive. The reason for this is surprisingly simple: we approach these problems with an outdated understanding of our world. While the world might still look similar to how it has looked for a long time, I will argue that it has, in fact, inconspicuously but fundamentally changed over time.

We are used to the idea that societies must be protected from external threats such as earthquakes, volcanic eruptions, hurricanes, and military attacks by enemies. However, we are increasingly threatened by another kind of problems: those that come from within the system, such as financial instabilities, economic crises, social and political unrest, organized crime and cybercrime, environmental change, and spreading diseases. These threats have become some of our greatest worries. According to the World Economic Forum's Risk Map, the largest risks today are of a socio-economic nature such as inequality or governance failure. These global 21st century problems cannot be solved with 20th century wisdom, because they are of a different scale and result from a new level of complexity in today's socio-economic systems. We must therefore better understand what complex systems are, and what are their properties. To this end, I will discuss the main reasons why things go wrong: unstable dynamics, cascading failures in networks, and systemic interdependencies. I will illustrate these problems by examples such as traffic jams, crowd disasters, blackouts, financial crises, crime, wars, and revolutions.

Phantom traffic jams

Complex systems include phenomena ranging from turbulent flows and the global weather system to decision-making, opinion formation in groups, financial and economic markets, and the evolution and spread of languages. But we must take care to distinguish complex systems from complicated ones. A car is complicated: it consists of thousands of parts, yet is easy to control (when it works properly). Traffic flow, on the other hand, which depends on the interactions of many cars, is a complex dynamical system, which produces counter-intuitive, individually uncontrollable behaviors such as "phantom traffic jams" that seem to have no cause. While many traffic jams do occur for a specific, identifiable reason, such as an accident or a building site, everyone has also encountered situations where a vehicle queue appeared "out of nothing" – and where there is no visible cause - see  visualisation

To explore the true reasons for these phantom traffic jams, Yuki Sugiyama from the Nagoya University in Japan and his colleagues carried out an experiment, in which they asked many people to drive their cars around a circular track - see visualisation  The task sounds simple, and indeed all vehicles moved smoothly for some time. But then a random perturbation in the traffic flow, an unexpected slow-down of a car, triggered the appearance of “stop-and-go” traffic – a traffic jam that travelled backwards around the track, against the driving direction.

While we often blame others for poor driving skills to explain such "phantom traffic jams," studies in complexity science have shown that they rather emerge as a collective phenomenon unavoidably resulting from the interactions between vehicles. A detailed analysis shows that, if the density of cars exceeds a certain "critical" threshold – that is, if their average separation is smaller than a certain value – then the smallest perturbation in the speed of any car will be amplified to cause a breakdown of the entire flow. Because drivers need some time to respond to such a disturbance, the next driver in line will have to brake harder to avoid an accident. Then the following driver will have to break even harder, and so on. This chain reaction amplifies the small initial perturbation and eventually produces the jam – which of course every individual would prefer to avoid.

Recessions - traffic jams in the world economy?

Economic supply chains might exhibit a similar kind of behavior. As known from John Sterman's "beer distribution game," supply chains are also hard to control. Even experienced managers will often end up ordering too much beer, or will run out of it. This is a situation that is as difficult to avoid as stop-and-go traffic. In fact, our scientific work suggests that economic recessions may be regarded as a kind of traffic jam in the global supply network (see figure below). This is actually somewhat heartening news, since it implies that, just as with traffic flow, engineered solutions may exist that can mitigate economic recessions, provided that we have access to real-time data on the world's supplies and materials flows. Such solutions will be discussed later in the chapter on Socio-Inspired Technologies.

Instability and self-organization in strongly interacting systems

A shocking example for systemic instabilities discussed later is the occurrence of crowd disasters. Here, even when everyone is peacefully minded and tries to avoid harming others, many people might die. What do all these examples tell us? Our experience will often not inform us well, and our intuition may fail, since complex dynamical systems tend to behave in unexpected or even counter-intuitive ways. Such systems are typically made up from many interacting components, which respond to the behavior of other system components. As a consequence of these interactions, complex dynamical systems tend to self-organize, i.e. to develop a collective behavior that is different from what the components would do in separation. Then, the components’ individual properties are often no longer characteristic for the system. "Chaotic" or "turbulent" dynamics are possible outcomes, but complex systems can show many other phenomena.

When self-organization occurs, one often speaks of emergent phenomena that are characterized by new system properties, which cannot be understood from the properties of the single components. For example, the facts that water feels wet, extinguishes fires, and freezes at a particular temperature are properties, which cannot be understood from the properties of single water molecules.

As a consequence of the above, we have to shift our attention from the components of our world to their interactions. In other words, we need a change from a component-oriented to an interaction-oriented, systemic view, which is at the heart of complexity science. I claim that this change in perspective, once it becomes common wisdom, will be of similar importance as the transition from the geocentric to the heliocentric worldview. The related paradigm shift has fundamental implications for the way in which complex techno-socio-economic systems must be managed and, hence, also for politics and our economy. Focusing on the interactions in a system and the multi-level emergent dynamics resulting from them, opens up fundamentally new solutions to long-standing problems.

Instability is one possible behavior of complex dynamical systems, which results when the characteristic system parameters cross certain critical thresholds. If a system behaves unstable, i.e. perturbations are amplified, a random, small deviation from the normal system state may trigger a domino effect that cannot be stopped, even if people have the best intentions to do so and have enough information, good technology, and proper training. In such situations of systemic instability, the system will inevitably get out of control sooner or later, no matter how hard we try to avoid this. As a consequence, we need to know the conditions under which systems will behave in an unstable way, in order to avoid such conditions. In many cases, too strong interactions are a recipe for disaster or other undesirable outcomes.

Group dynamics and mass psychology may be seen as typical examples of collective dynamics. People have often wondered what makes a crowd turn "mad", violent, or cruel. After the London riots in the year 2011, people asked how it was possible that teachers and daughters of millionaires – people one would not expect to be criminals – were participating in the lootings. Did they become criminal minds when their demonstrations against police violence suddenly turned into riots? Possibly, but not necessarily so. In the above traffic flow example, people wanted to do one thing: drive continuously at reasonably high speed, but a phantom traffic jam occurred instead. We found that, while individual cars are well controllable, the traffic flow – a result of the interactions of many cars – is often not. The take home message may be formulated as follows: complex systems cannot be steered like a car. Even if everyone has the latest technology, is well-informed and well-trained, and has the best intentions, an unstable complex system will sooner or later get out of control.

Therefore, while our intuition works well for weakly coupled systems, in which the system properties can be understood as sum of the component properties, complex dynamical systems behave often in counter-intuitive, hardly predictable ways. Frequently, the collective, macro-level outcome in a complex system can't be understood from and controlled by the system components. (Such system components might also be individuals or companies, for example.)

Beware of strongly coupled systems

Thus, what tends to be different in strongly coupled systems as compared to weakly interacting ones? First, the dynamics of strongly connected systems with positive feedbacks is often faster. Second, self-organization and strong correlations tend to dominate the dynamics of the system. Third, the system behavior is often counter-intuitive – unwanted feedback or side effects are common. Conventional wisdom tends to fail. In particular, extreme events occur more often than expected, and they may impact the entire system. Furthermore, the system behavior can be hard to predict, and planning for the future may not be useful. Opportunities for external control are also typically quite limited, as the system-immanent interactions tend to dominate. Finally, the loss of predictability and control may lead to an erosion of trust in private and public institutions, which in turn can create social, political, or economic instabilities.

In spite of all this, many people still have a component-oriented and individual-centric view, which can be quite misleading. We praise heroes when things run well and search for scapegoats when something goes wrong. But the discussion above has shown how difficult it is for individuals to control the outcome of a complex dynamical system, if its components' interactions are strong. This fact may be illustrated by the example of politics. Why do politicians, besides managers, have among the worst reputations among all professions? This is probably because we vote them to make politics according to the positions they publicly voice, but then we often find them doing something else. This, again, is a consequence of the fact that politicians are exposed to many strong interactions due to lobbyists and pressure groups with various points of view. Each one is trying to push the politician in a different direction. In many cases, this will force the politician to take a decision that is not compatible with his or her own points of view, which is hard for the voters to accept. Managers of companies find themselves in similar situations. But not only they: think of the decision-dynamics in many families. If it were easy to control, we would not see so many divorces...

Crime is another good example for unwanted outcomes of complex dynamics, even though a controversial one. We must ask ourselves: Are we interested in sustaining social order, or are we interested in filling prisons? If we decide for the first option, we must confront ourselves with the question: Should we really see all crime as deeds of criminal minds, as we often do? Or should we pay more attention to the circumstances that happen to cause crime? In cases, where individuals plan crimes such as the theft of a famous diamond, the conventional picture of crime is certainly appropriate. But do these cases give a representative picture?

Classically, it is assumed that crimes are committed, if the expected advantage is larger than the punishment, multiplied with the probability of being convicted. Therefore, raising punishments and discovery rates should theoretically eliminate all crime. Such punishment would make crime a lossful experience and, therefore, "unattractive." However, empirical evidence questions this simple picture. On the one hand, people usually don't pick pockets, even though they could often get away without a punishment. On the other hand, deterrence strategies are surprisingly ineffective in most countries, and high crime rates are often recurrent. For example, even though the USA have 10 times more prisoners than most European countries, rates of various crimes, including homicides, are still much higher. So, what is wrong with our common understanding of crime?

Surprisingly, many crimes, including murders, are committed by average people, not by people with criminal careers. A closer inspection shows that many crimes result from situations, over which the involved individuals lose their control. Frequently, group dynamics plays an important role, and many scientific studies indicate that the socio-economic context is a strong determining factor of crime. Therefore, in order to counter crime, it might be more effective to change these socio-economic conditions rather than sending more people to jail. I am saying this also with an eye on the price we have to pay for this: A single prisoner costs more than the salary of a postdoctoral researcher with a PhD degree, some even more than a professor!

Cascade effects in complex networks

Making things worse, complex systems may show further problems besides dynamic instabilities based on amplification effects. Thanks to globalization and technological progress, we have now a global exchange of people, goods, money, and information. Worldwide trade, air traffic, the Internet, mobile phones, and social media have made everything much more comfortable – and connected. This has created many new opportunities, but everything now depends on a lot more things. What are the implications of this increased interdependency? Today, a single tweet can send stock markets to hell. A youtube movie can trigger a riot that kills dozens of people. Our decisions can have impacts on the other side of the globe more easily than ever – and sometimes unintentionally so. For example, today’s quick spreading of emerging epidemics is largely a result of global air traffic, and can seriously affect global health, social welfare, and economic systems.

By networking our world, have we inadvertently built highways for disaster spreading? In 2011 alone, three major cascading failures occurred, which are changing the face of the world and the global balance of power: The financial crisis, the Arab spring and the combined earthquake, tsunami and nuclear disaster in Japan. In the following, I will discuss some examples of cascade effects in more detail.

Large-scale power blackouts

On November 4, 2006, a power line was temporarily turned off in Ems, Germany, to facilitate the transfer of a Norwegian ship. Within minutes, this caused a blackout in many regions all over Europe – from Germany to Portugal! Nobody expected this. Before the line was switched off, of course, a computer simulation was performed to verify that the power grid would still operate well. But the scenario analysis did not check for the coincidence of a spontaneous failure of another line. In the end, a local overload of the grid caused emergency switch-offs in the neighborhood, creating a cascade effect with pretty astonishing outcomes: some blackouts occurred in regions thousands of kilometers away, while other areas in the neighborhood were not affected at all. Is it possible to understand this strange behavior?

Indeed, a computer-based simulation study of the European power grid recently managed to reproduce such effects. It demonstrated that the failure of a few network nodes in Spain could create a surprising blackout in Eastern Europe, several thousand kilometers away, while the electricity network in Spain would still work - see visualisation

Furthermore, increasing the capacities of certain parts of the power grid would unexpectedly make things worse. The cascading failure would be even bigger! Therefore, weak elements in the system have an important function: they act as circuit breakers, thereby interrupting the failure cascade. This is an important fact to remember.

Bankruptcy cascades

The sudden financial meltdown in 2008 is another example, which hit many companies and people by surprise. In a presidential address to the American Economic Association in 2003, Robert Lucas said:
"[The] central problem of depression-prevention has been solved."
Similarly, Ben Barnenke, as chairman of the Federal Reserve Board, long believed that the economy was well understood, and doing well. In September 2007, Ric Mishkin, a professor at Columbia Business School and then a member of the Board of Governors of the US Federal Reserve System, made a statement reflecting widespread beliefs at this time:
"Fortunately, the overall financial system appears to be in good health, and the U.S. banking system is well positioned to withstand stressful market conditions."

As we all know, things came very different. A banking crisis occurred only shortly later. It started locally, with the bursting of a real estate bubble in the West of the USA. Because of this locality, most people thought this problem was easy to contain. But the mortgage crises had spill-over effects to the stock markets, where certain financial derivatives could not be sold anymore (now called "toxic assets"). Eventually, more than 400 banks all over the United States went bankrupt. How could this happen? The video presents an impressive visualisation of the bankruptcies of banks in the USA after Lehman Brothers collapsed. Apparently, one bank's default triggered further ones, and these triggered even more. In the end, hundreds of billion dollars were lost.

The above video reminds of another video which I often use to illustrate cascade effects: It shows an experiment with many table tennis balls placed on top of mouse traps. The experiment demonstrates impressively that a single local perturbation can mess up the entire system. It illustrates chain reactions, which are the basis of atomic bombs or of nuclear fission reactors. As we know, such cascade effects are technologically controllable in principle, if we stay below the critical interaction strength (sometimes called the "critical mass"). Nevertheless, these processes can sometimes get out of control, mostly in unexpected ways. The nuclear disasters in Chernobyl or in Fukushima are well-known examples for this. So, we must be extremely careful with systems showing cascade effects.

The financial crisis

As we know, the above-mentioned cascading failure of banks was just the beginning of an even bigger crisis. It subsequently caused an economic crisis and a public spending crisis in major areas of the world. Eventually, the events even threatened the stability of the Euro currency and the European Union. The crisis brought several countries (including Greece, Ireland, Portugal, Spain, Italy and the US) at the verge of bankruptcy. As a consequence, many countries have seen historical heights in unemployment rates. In some countries, more than 50 percent of young people do not have a job. In many regions, this has caused social unrests, political extremism and increased crime and violence. Unfortunately, it seems that the cascade effect has not been stopped yet. There is a long way to go until we fully recover from the financial crisis and from the public and private debts accumulated in the past years. If we can't overcome this problem soon, it has even the potential to endanger peace, democratic principles and cultural values, as I pointed out in a letter to George Soros in 2010. Looking at the situation in Ukraine, we are perhaps seeing this scenario already.

While all of this is now plausible from hindsight, the lack of advance understanding by conventional wisdom becomes clear by the following quote from November 2010, going back to the former president of the European Central Bank, Jean-Claude Trichet:

"When the crisis came, the serious limitations of existing economic and financial models immediately became apparent. Arbitrage broke down in many market segments, as markets froze and market participants were gripped by panic. Macro models failed to predict the crisis and seemed incapable of explaining what was happening to the economy in a convincing manner. As a policy-maker during the crisis, I found the available models of limited help. In fact, I would go further: in the face of the crisis, we felt abandoned by conventional tools." Similarly, Ben Bernanke summarized in May 2010: “The brief market plunge was just an example of how complex and chaotic, in a formal sense, these systems have become… What happened in the stock market is just a little example of how things can cascade, or how technology can interact with market panic.”

Leading scientists as well had problems making sense of the crisis. In a letter dated 22 July 2009 to the Queen of England, the British Academy came to the conclusion:

"When Your Majesty visited the London School of Economics last November, you quite rightly asked: why had nobody noticed that the credit crunch was on its way? ... So where was the problem? Everyone seemed to be doing their own job properly on its own merit. And according to standard measures of success, they were often doing it well. The failure was to see how collectively this added up to a series of interconnected imbalances over which no single authority had jurisdiction. ... Individual risks may rightly have been viewed as small, but the risk to the system as a whole was vast. ... So in summary ... the failure to foresee the timing, extent and severity of the crisis … was principally the failure of the collective imagination of many bright people to understand the risks to the systems as a whole."

Thus, nobody was responsible for the financial mess? I don't want to judge, but we should remember that it's often not possible to point the finger at the exact person who caused a phantom traffic jam. Therefore, given that these are collectively produced outcomes, do we have to accept collective responsibility for them? And how to enumerate everyone's share of responsibility? This is certainly an important question worth thinking about.

It is also interesting to ask, whether complexity science could have forecasted the financial crisis? In fact, before the crash, I followed the stock markets pretty closely, as I noticed strong price fluctuations, which I interpreted as "critical fluctuations," i.e. an advance warning signal of an impending financial crash. Therefore, I sold my stocks in the business launch of an airport in 2007, while waiting for the departure of my airplane. In spring 2008, about half a year before the collapse of Lehman brothers, I wrote an article together with Markus Christen and James Breiding, taking a complexity science perspective on the financial system. We came to the conclusion that the financial system was in a process of destabilization. Pretty much as Andrew Haldane, Chief Economist and Executive Director at the Bank of England, formulated it later, we believed that the increased level of complexity in the financial system was a major problem. It made the financial system more vulnerable to cascade effects than most experts thought. In spring 2008, we were so worried about this that we felt we had to alert the public, but none of the newspapers we contacted was ready to publish our essay at that time. "Too complicated for our readers" was the response, while we replied "if you cannot make this understandable to your readers, then there is nothing that can prevent the financial crisis." And so the financial crisis came! Six month after the crisis, a manager of McKinsey in the United Kingdom commented on our analysis that it was the best he had ever seen.

But there were much more prominent people who saw the financial crisis coming. For example, legendary investor Warren Buffet warned of mega-catastrophic risks created by large-scale investments into financial derivatives. Back in 2002 he wrote:

"Many people argue that derivatives reduce systemic problems, in that participants who can't bear certain risks are able to transfer them to stronger hands. These people believe that derivatives act to stabilize the economy, facilitate trade, and eliminate bumps for individual participants. On a micro level, what they say is often true. I believe, however, that the macro picture is dangerous and getting more so. ... The derivatives genie is now well out of the bottle, and these instruments will almost certainly multiply in variety and number until some event makes their toxicity clear. Central banks and governments have so far found no effective way to control, or even monitor, the risks posed by these contracts. In my view, derivatives are financial weapons of mass destruction, carrying dangers that, while now latent, are potentially lethal."
As we know, it still took five years until the "investment time bomb" exploded, causing losses of trillions of dollars to our economy.

Fundamental uncertainty

In liquid financial markets and many other hardly predictable systems such as the weather, we can still determine the probability of events, at least approximately. Thus, we make a probabilistic forecast similar to: "there is a 5 percent chance to lose more than half of my money when selling my stocks in 6 months, but a 70 percent chance that I will make a good profit, etc." It is then possible to determine the expected loss (or gain) implied by the likely actions and events. For this purpose, the damage or gain of each possible event is multiplied with its probability, and the numbers are added up to give the expected damage or gain. In principle, one could do this for all actions we might take, in order to determine the one that minimizes the damage or maximizes the gain. The only problem involved in this exercise seems to be the practical determination of the probabilities and of the likely damages or gains involved. With the increasing availability of data, this problem might, in fact, be attacked, but it will remain difficult or impossible to determine the probabilities of "extreme events," as the empirical basis for rare events is too small.

It turns out, however, that there are problems where the expected damage in large (global) systems cannot be determined at all for principal reasons. Such "fundamental" or "radical" uncertainty can occur in case of cascade effects, where one failure is likely to trigger other failures, and where the damage related to subsequent events times their likelihood is increasing. In such cases, the sum of losses may be unbounded, in principle, i.e. it may not be possible anymore to enumerate the expected loss. In practice, this means that the actual damage can be small, big, or practically unbounded, where the latter might lead to the collapse of the entire system.

Explosive pandemic outbreaks

The threat by cascade effects might be even worse if the damage occurring in an early phase of the cascade process reduces the probability of resisting failures that are triggered later. A health system, in which financial or medical resources are limited, may be considered as an example for this. How will this system deal with emergent diseases? A computer-based study that I performed together with Lucas B├Âttcher, Nuno Araujo, Olivia Woolley Meza and Hans Hermann shows that the outcome very much depends on the connectivity between people who may infect each other. A few additional airline connections can make the difference between a case, where the disease will be contained, and where it turns into a devastating global pandemics. The problem is that crossing a certain connectivity threshold will change the system dynamics dramatically and unexpectedly. Thus, have we built global networks that behave in unpredictable and uncontrollable ways?

Systemic interdependencies

Recently, Shlomo Havlin and others made a further important discovery: they revealed that networks of networks can be particularly vulnerable to failures. A typical example is the interdependency between electrical and communication networks. Another example, which illustrates the global interdependencies between natural, energy, climate, financial, and political systems is the following: In 2011, the Tohoku earthquake in Japan caused a tsunami that triggered chain reactions and nuclear disasters in several reactors at Fukushima. Soon after this, Germany and Switzerland decided to exit nuclear power generation over the next decade(s). However, alternative energy scenarios turn out to be problematic as well. European gas deliveries depend on some regions, which we cannot fully rely on. Likewise, Europe’s DESERTEC project, a planned 1000 billion Euro investment into infrastructure to supply solar energy for Europe – has an uncertain future due to another unexpected event, the Arab Spring. This was triggered by high food prices, which were no longer affordable to many people. These high food prices, in turn, resulted partly from biofuel production, which intended to improve the global CO2 balance, but competed with food production. The increasing food prices were further amplified by financial speculation. Hence, the energy system, the political system, the social system, the food system, the financial system – they have all become closely interdependent systems, which makes our world ever more vulnerable to perturbations.

Have humans unintentionally created a "complexity time bomb"?

We have seen that, when systems are too much connected, they might get out of control sooner or later, despite advanced knowledge and technology, and best intentions to keep things under control. Therefore, as we have created more and more links and interdependencies in the world, we must ask ourselves: have humans inadvertently produced a "complexity time bomb", a system that will ultimately get out of control?

For a long time, problems such as crowd disasters and financial crashes have been seen as puzzling, ‘God-given’ phenomena or "black swans" one had to live with. However, problems like these should not be considered “bad luck.” They are often the consequence of a flawed understanding of counter-intuitive system behaviors. While conventional thinking can cause fateful decisions and the repetition of previous mistakes, complexity science allows us to understand the mechanisms that cause complex systems to get out of control. Amplification effects can result and promote failure cascades, when the interactions of system components become stronger than the frictional effects or when the damaging impact of impaired system components on other components occurs faster than the recovery to their normal state. That is, time scales of processes largely determine the controllability of a system as well. Delayed adaptation processes are often responsible for systemic instabilities and losses of control (see the related Information Box at the end).

For certain kinds of networks, the similarity of related cascade effects with those of chain reactions in nuclear fission is quite disturbing. Such processes are difficult to control. Catastrophic damage is a realistic scenario. Therefore, given the similarity of the cascading mechanisms, is it possible that our worldwide anthropogenic system will get out of control sooner or later? When analyzing this possibility, one must bear in mind that the speed of destructive cascade effects might be slow, and the process may not appear like an explosion. Nevertheless, the process may be hard to stop and lead to an ultimate systemic failure. For example, the dynamics underlying crowd disasters is slow, but deadly. So, what kinds of global catastrophic scenarios might we face in complex societies? A collapse of the global information and communication systems or of the world economy? Global pandemics? Unsustainable growth, demographic or environmental change? A global food or energy crisis? A cultural clash? Another global-scale war? A societal shift, driven by technological innovations? Or, more likely, a combination of several of these contagious phenomena? The World Economic Forum calls this the "perfect storm," and the OECD has formulated similar concerns.

Unintended wars and revolutions

Last but not least, it is important to realize that large-scale conflicts, revolutions, and wars can also be unintended results of systemic instabilities and interdependencies. Interpreting them as deeds of historical figures personalizes these phenomena in a way that distracts from their true, systemic nature. It is important to recognize that complex systems such as our economy or societies usually resist attempts to change them at large, namely when they are close to a stable equilibrium. This is also known as Goodhart's law (1975), principle of Le Chatelier (1850-1936), or as "illusion of control." Individual factors and randomness can only have a large impact on the path taken by the complex system, when the system is driven to a tipping point (also known as "critical point"). In other words, instability is a precondition for individuals to have a historical impact. For example, the historical sciences increasingly recognize that World War I was pretty much an unintended, emergent outcome of a chain reaction of events. Moreover, World War II was preceded by a financial crisis and recession, which destabilized the German economic, social, and political system. This finally made it possible that an individual could become influential enough to drive the world to the edge.

Unfortunately, civilization is vulnerable, and a large-scale war may happen again – I would say, it is even likely. A typical unintended path towards war looks as follows: The resource situation deteriorates, for example, because of a serious economic crisis. The resulting fierce competition for limited resources lets competition, violence, crime, and corruption rise, while solidarity and tolerance go down, so that the society is fragmented into groups. This causes conflict, further dissatisfaction and social turmoil. People get frustrated about the system, calling for leadership and order. Political extremism emerges, scapegoats are searched, and minorities are put under pressure. As a consequence, socio-economic diversity is lost, which further reduces the economic success of the system. Eventually, the well-balanced "socio-economic ecosystem" collapses, such that the resource situation (the apparent "carrying capacity") deteriorates. This destabilizes the system further, such that an external enemy is "needed" to re-stabilize the country. Finally, nationalism rises, and war may seem to be the only "solution" to keep the country together.

Note that a revolution, too, can be the result of systemic instability. Hence, it does not need to be initiated by an individual, "revolutionary" leader, who challenges an established political system. The breakdown of the former German Democratic Republic (GDR) and some Arab spring revolutions (for example, in Libya) have shown that revolutions may start even without the existence of a clearly identifiable political opponent leading the revolution. On the one hand, this is the reason, why such revolutions cannot be stopped by targeting a few individuals and sending them to jail. On the other hand, the absence of revolutionary leaders has puzzled secret services around the world – the Arabic spring took them by surprise. It was also irritating for sympathetic countries, which could not easily provide support for democratic civil movements. Whom should they have talked or given money to?

It provides a better picture to imagine such revolutions as a result of situations, in which the interest of government representatives and the people (or the interests of different societal groups) have drifted away from each other. Similar to tensions created by the drift of the Earth's tectonic plates, this would sooner or later lead to an unstable situation and an "earthquake-like" stress release (the "revolution"), resulting in a re-balancing of forces. Again, it is a systemic instability, which allows individuals or small groups to become influential eventually, while the conventional picture suggests that the instability of a political regime is caused by a revolutionary leader. Putting it differently, a revolution isn't usually the result of the new political leaders, but of the politics that was made before, which destabilized the system. So, we should ask ourselves, how well are our societies doing in terms of balancing the different interests in our societies, and in terms of adapting to a quickly changing world, due to demographic change, environmental change, technological change?


It is obvious that there are many problems ahead of us. Most of them result from the complexity of the systems humans have created. But how can we master all these problems? Is it a lost battle against complexity? Or do we have to pursue a new, entirely different strategy? Do we perhaps even need to change our way of thinking? And how can we generate the innovations needed, before it's too late? The next chapters will let you know...

Information Box: How harmless behavior can turn critical

In the traffic flow example and for the case of crowd disasters, we have seen that a system can get out of control when the interaction strength (e.g. the density) is too large.

How a change in density can turn harmless behavior of system components uncontrollable, is illustrated by the following example: Together with Roman Mani, Lucas B├Âttcher, and Hans J. Herrmann, I studied collisions in a system of equally sized particles moving in one dimension, similar to Newton's Cradle see video. We assumed that the particles tended to oscillate elastically around equally spaced equilibrium points, while being exposed to random forces generated by the environment. If the distance between the equilibrium points of neighboring particles was large enough, each particle oscillated around its equilibrium point with normally distributed speeds, and all particles had the same small variance in speeds.

However, as the separation of equilibrium points approached the particle diameter, we found a cascade-like transmission of momentum between particles see video. Surprisingly, towards the boundary particles, the variance of speeds was rapidly increasing. In energy-conserving systems, the speed variance of the outer particles would even tend towards infinity with increasing system size. Due to cascading particle interactions, this makes their speeds unpredictable and uncontrollable, even though every particle follows a simple and harmless dynamics.

Information Box: Loss of Synchronization

There is another puzzling kind of systemic instability that is highly relevant for our societies, as many socio-economic processes accelerate. It occurs when the separation of time scales gets lost. For example, hierarchical systems in physics and biology are characterized by the fact that adjustment processes on higher hierarchical levels are typically much slower than on lower hierarchical levels. Therefore, lower level variables adjust quickly to the constraints set by the higher level ones, and that is why the higher levels basically control the lower ones. For example, groups tend to take decisions more slowly than the individuals forming them, and the organizations and states made up from them change even more slowly (at least it has been like this in the past).
Time scale separation implies that the system dynamics is determined by a few variables only, which are typically related to the higher hierarchy levels. Monarchies and oligarchies are good examples for this. In current socio-political and economic systems, however, we observe the trend that higher hierarchical levels show accelerating speeds of adjustment, such that the lower levels can no longer adjust more quickly than the higher levels. This may eventually destroy time scale separation, such that many more variables start to influence the system dynamics. The result of such mutual adjustment attempts on different hierarchical levels could be turbulence, "chaos," or a breakdown of synchronization. In fact, systems often get out of control, if the adjustment processes are not quick enough and responses to changed conditions are delayed.