Get Savvy with Systems

The 2008 financial crisis has shown that supply and demand equilibrium is not a “law”. Rather than ready-made theories, economics needs the experimental background provided by systems thinking.

This post is part of a reading series of Doughnut Economics by Kate Raworth. For quick access to all chapters, click here.

As in any book club, you are kindly invited to let the rest of us know what you think!

Disclaimer: Being the result of personal work, this chapter summary cannot and does not pretend to offer a detailed and accurate transcription of all the author’s ideas.

Overcoming Our Inheritance

Get Savvy with Systems
William Stanley Jevons (1835 – 1882)

To the 19th-century economist William Stanley Jevons, the laws of economics were supposed to be as absolute as the law of gravity itself. And since Newtonian physics explained the world from the atomic to the planetary level, Jevons thought the market should too—from the behavior of a single consumer to the national output. In his own words: “Just as we measure gravity by its effects in the motion of a pendulum, so we may estimate the equality or inequality of feelings by the decisions of the human mind. The will is our pendulum, and its oscillations are minutely registered in the price lists of the markets. I know not when we shall have a perfect system of statistics, but the want of it is the only insuperable obstacle in the way of making Economics an exact science.”1

What is expressed in these lines is the theory of equilibrium, set to become one of the pillars of classical economics. Kate Raworth explains further: “Crucially the nascent theory hinged on assuming that, for any given mix of preferences that consumers might have, there was just one price at which everyone who wanted to buy and everyone who wanted to sell would be satisfied, having bought or sold all that they wanted for that price. In other words, each market had to have one single, stable point of equilibrium, just as a pendulum has only one point of rest. And for that condition to hold, the market’s buyers and sellers all had to be ‘price-takers’—no single actor being big enough to have sway over prices—and they had to be following the law of diminishing returns.” (Raworth, Kate. Doughnut Economics: Seven Ways to Think Like a 21st-Century Economist, p. 114).

Get Savvy with Systems

This is what the diagram of supply and demand illustrates. The market price is not set by suppliers’ costs nor by consumers’ utility alone, but precisely where costs and utility meet—and there lies the point of market equilibrium. According to the theory, furthermore, “if those markets were comprised of fully informed, small-scale, competitive sellers and buyers, then the economy would reach a point of equilibrium that maximised total utility. In other words—in a neat echo of Smith’s invisible hand—it would, for any given income distribution, produce the best possible outcome for society as a whole.” (Id. p. 115) The full mathematical model of general equilibrium was provided in the mid-1950’s. “It appeared to be a landmark proof, giving microeconomic underpinning to macroeconomic analysis, launching a seemingly unified economic theory and laying the foundations of what has been known ever since as ‘modern macro’.” (Id.)

The theory of equilibrium is nevertheless a pure abstraction, as the 2008 financial crisis made clear. Its inability to predict boom, bust, or depression shows that it has no foundations to hold to in the real world. One economist, in particular, took upon himself to enlighten the public about the issue. Not any economist. “Robert Solow, known as the father of neoclassical economic growth theory and long-time collaborator of Paul Samuelson, became an outspoken critic [of the equilibrium theory], first in his 2003 speech bluntly entitled ‘Dumb and Dumber in Macroeconomics’, then in analyses that mocked the theory’s stringent assumptions.2 The general equilibrium model, he pointed out, in fact depends upon there being just one single, immortal consumer-worker-owner maximising their utility into an infinite future, with perfect foresight and rational expectations, all the while served by perfectly competitive firms. How on Earth did such absurd models come to be so dominant? In 2008, Solow gave his view:

Get Savvy with Systems
Robert Solow

‘I am left with a puzzle, or even a challenge. What accounts for the ability of ‘modern macro’ to win hearts and minds among bright and enterprising academic economists? . . . There has always been a purist streak in economics that wants everything to follow neatly from greed, rationality, and equilibrium, with no ifs, ands, or buts . . . The theory is neat, learnable, not terribly difficult, but just technical enough to feel like ‘science.’ Moreover it is practically guaranteed to give laissez-faire-type advice, which happens to fit nicely with the general turn to the political right that began in the 1970s and may or may not be coming to an end.3‘” (Id. p. 116)

The truth of the matter is that generations of economists have deluded themselves in thinking that scientific evidence is of one type only. Among many other sources, Warren Weaver, who was then director of natural sciences at the Rockefeller Foundation, wrote in 1948 an article titled Science and Complexity where the necessary distinctions are clearly laid out. There are, basically, three kinds of problems that science can help us to understand: “At one extreme lie problems of simplicity, involving just one or two variables in linear causality—a rolling billiard ball, a falling apple, an orbiting planet—and Newton’s laws of classical mechanics do a great job of explaining these. At the other extreme, he wrote, are problems of disordered complexity involving the random movement of billions of variables—such as the motion of molecules in a gas—and these are best analysed using statistics and probability theory. In between these two branches of science, however, lies a vast and fascinating realm: problems of organised complexity, which involve a sizeable number of variables that are ‘interrelated in an organic whole’ to create a complex but organised system.” (Id. p. 117)

Get Savvy with Systems
Warren Weaver (1894 – 1978)

“Weaver’s examples, adds Kate Raworth, came close to asking the very questions that Newton’s apple failed to prompt. ‘What makes an evening primrose open when it does? Why does salt water fail to satisfy thirst? . . . Is a virus a living organism?’ He noted that economic questions came into this realm, too. ‘On what does the price of wheat depend? . . . To what extent is it safe to depend on the free interplay of such economic forces as supply and demand? . . . To what extent must systems of economic control be employed to prevent the wide swings from prosperity to depression?’ Indeed, Weaver recognised that most of humanity’s biological, ecological, economic, social and political challenges were questions of organised complexity, the realm that was least understood.” (Id.)

Studying how relationships between the many parts of a system shape the behavior of the whole would become a science in the 1970s. This is how we can overcome our inheritance in the field of economics.

The Dance of Complexity

Get Savvy with Systems

“At the heart of systems thinking lie three deceptively simple concepts: stocks and flows, feedback loops, and delay. They sound straightforward enough, but the mind-boggling business begins when they start to interact.” (Id. p. 118)

“Stocks and flows are the basic elements of any system: things that can get built up or run down—just like water in a bath, fish in the sea, people on the planet, trust in a community, or money in the bank. A stock’s levels change over time due to the balance between its inflows and outflows.” (Id. p. 119)

Get Savvy with Systems

If stocks and flows are a system’s core elements, then feedback loops are their interconnections, and in every system, there are two kinds: reinforcing (or ‘positive’) feedback loops and balancing (or ‘negative’) ones. With reinforcing feedback loops, the more you have, the more you get. They amplify what is happening, creating vicious or virtuous circles that will, if unchecked, lead either to explosive growth or to collapse. (…) If reinforcing feedbacks are what make a system move, then balancing feedbacks are what stop it from exploding or imploding. They counter and offset what is happening and, so, tend to regulate systems. Our bodies use balancing feedbacks to maintain a healthy temperature: get too hot and your skin will start sweating in order to cool you down; get too cold and your body will start shivering in an attempt to warm itself up.” (Id.)

Lastly, delays between inflows and outflows “are common in systems and can have big effects. Sometimes they bring useful stability to a system, allowing stocks to build up and act as buffers or shock absorbers: think energy stored in a battery, food in the cupboard or savings in the bank. But stock–flow delays can produce system stubbornness too: no matter how much effort gets put in, it takes time to, say, reforest a hillside, build trust in a community, or improve a school’s exam grades. And delay can generate big oscillations when systems are slow to respond—as anyone knows who has been scalded then frozen then scalded again while trying to master the taps on an unfamiliar shower.” (Id. pp. 120-121).

“It is out of these interactions of stocks, flows, feedbacks and delays that complex adaptive systems arise: complex due to their unpredictable emergent behaviour, and adaptive because they keep evolving over time. (…) it soon becomes clear just how powerful systems thinking can be for understanding our ever-evolving world, from the rise of corporate empires to the collapse of ecosystems.” (Id. p. 121)

Complexity in Economics

Here is for systems thinking in a nutshell.4 Let’s consider the shortcomings of the equilibrium theory in that light. One of them is that this theory forces downplaying instability as a result of the economical dynamics themselves. Taking the financial crisis of 2008 as an example again, Kate Raworth states that “In the decade running up to the crash, and oblivious to the build-up of systemic risk, the UK’s chancellor, Gordon Brown, hailed the end of boom and bust,5 while Ben Bernanke, Governor of the Federal Reserve Board welcomed what he called ‘the Great Moderation’.6After 2008, when the boom went very bust, Gordon Brown explicitly admitted “we created a monitoring system that was looking at individual institutions. That was the big mistake. We didn’t understand how risk was spread across the system, we didn’t understand the entanglements of different institutions with each other, and we didn’t understand—even though we talked about it—just how global things were.”7

Another thing that the equilibrium theory downplays is the fostering of inequality. “Given that markets are efficient at rewarding people, goes the theory, then those with broadly similar talents, preferences and initial endowments will end up equally rewarded: any remaining differences must be due to differences in effort, and that provides a spur for innovation and hard work. But in the disequilibrium world that we inhabit—where powerful reinforcing feedbacks are in play—virtuous cycles of wealth and vicious cycles of poverty can send otherwise similar people spiralling to opposite ends of the income-distribution spectrum.” (Id. p. 127)

But the main lesson is that by ignoring systems with their stocks and flows, feedback loops, and delay mechanisms, the equilibrium theory has been an important intellectual driver in bringing the world to the verge of collapse. In 1972 the study Limits to Growth8 was published by a team of authors based at MIT, who had created one of the first dynamic computer models of the global economy, known as World 3, in order to explore a range of economic scenarios up to 2100. Five factors were chosen as determining—and ultimately limiting—output growth: population, agricultural production, natural resources, industrial production, and pollution. The economic scenario of business-as-usual turned out to be alarming. Unfortunately, the modelization has, since then, proved to be accurate.9

Get Savvy with Systems

As one could have expected, however, “Mainstream economists were quick to deride the model’s design on the basis that it underplayed the balancing feedback of the price mechanism in markets. If non-renewable resources became scarce, they argued, their prices would rise, triggering greater efficiency in their use, the wider use of substitutes and exploration for new sources.” (Id.) In theory. In practice, indefinite growth still does not make sense on a finite planet. Not only does Earth hold a finite quantity of resources but she also has a finite capacity to recycle our waste. As for the latter, “Such negative externalities, remarks the ecological economist Herman Daly, are those things that ‘we classify as “external” costs for no better reason than because we have made no provision for them in our economic theories’.”10 (Id. p. 123) The externalities of pollution and environmental degradation typically carry no price, and so generate no direct market feedback, even though they are real. By taking into account the limits we are confronted to on this planet we see as our home, system thinking proves to be definitely more accurate than a fake economic science that creates its own truths out of thin air.

Goodbye Wrench, Hello Pruners

How can the dynamics of stocks and flows, feedback loops, and delays be applied to to forge a sustainable economy? Kate Raworth first set the terms of the debate to then answer the question.

“Today’s economy is divisive and degenerative by default. Tomorrow’s economy must be distributive and regenerative by design. An economy that is distributive by design is one whose dynamics tend to disperse and circulate value as it is created, rather than concentrating it in ever-fewer hands. An economy that is regenerative by design is one in which people become full participants in regenerating Earth’s life-giving cycles so that we thrive within planetary boundaries.” (Id. p. 133)

“In their book The Gardens of Democracy, Eric Lui and Nick Hanauer argue that moving from ‘machinebrain’ to ‘gardenbrain’ thinking calls for a simultaneous shift away from believing that things will self-regulate to realising that things need stewarding. ‘To be a gardener is not to let nature take its course; it is to tend,’ they write. ‘Gardeners don’t make plants grow but they do create conditions where plants can thrive and they do make judgments about what should and shouldn’t be in the garden.’”11 (Id. p. 135)

Get Savvy with Systems
Charlie Chaplin – Modern Times (1936)
Get Savvy with Systems
Josephine Baker at her Château des Milandes, in France.

“One approach to economic gardening is to embrace evolution. Rather than aiming to predict and control the economy’s behaviour, says Eric Beinhocker (a leading thinker in this field) economists should ‘think of policy as an adapting portfolio of experiments that helps to shape the evolution of the economy and society over time.’ It’s an approach that aims to mimic the process of natural selection, often summed up as ‘diversify–select–amplify’. Set up small-scale policy experiments to test out a variety of interventions, put a stop to the ones that don’t work well, and scale up those that do.”12

How to achieve that? Effective systems tend to have three properties—healthy hierarchy, self-organisation and resilience, thus the economy should be stewarded to enable these characteristics to emerge.

“First, healthy hierarchy is achieved when nested systems serve the greater whole of which they are a part. Liver cells serve the liver, which in turn serves the human body; if those cells start to multiply rapidly, they become a cancer, no longer serving but destroying the body on which they depend. In economic terms, healthy hierarchy means, for example, ensuring that the financial sector is in service to the productive economy, which in turn is in service to life.50 Second, self-organisation is born out of a system’s capacity to make its own structures more complex, such as a dividing cell, a growing social movement or an expanding city. In the economy, much self-organising goes on in the marketplace through the price mechanism (that was Adam Smith’s insight), but it also takes place in the commons and in the household too (the insight of Elinor Ostrom and generations of feminist economists). All three of these realms of provisioning can self-organise effectively to meet people’s wants and needs, and the state should support all three in doing so. Lastly, resilience emerges out of a system’s ability to endure and bounce back from stress, like a jelly that wobbles on a plate without losing its form or a spider’s web that survives a storm. Equilibrium economics became fixated on maximising efficiency and so overlooked the vulnerability that it can bring, as we will see in the next chapter. Building diversity and redundancy into economic structures enhances the economy’s resilience, making it far more effective in adapting to future shocks and pressures.” (Id. pp. 136-137)

Book Club Discussion: How do you make sense of stocks and flows, feedback loops, and delays? According to you, could and/or should systems thinking become the pattern of mainstream economics?

Share your thoughts and build on what others say in the comment section below.


  1. Jevons, W.S. (1871) The Theory of Political Economy (1.17), available at
  2. Solow, R. (2003) ‘Dumb and dumber in macroeconomics’. Speech given in honour of Joseph Stiglitz’s 60th birthday, available at
  3. Solow, R. (2008) ‘The state of macroeconomics’, Journal of Economic Perspectives 22: 1, pp. 243–249.
  4. For a more complete view, see Thinking in Systems – A Primer
  5. Brown, G. (1999) Speech to the Labour Party Conference, 27 September 1999.
  6. Bernanke, B. (2004) ‘The great moderation’. Remarks at the meeting of the Eastern Economic Association, Washington, DC, 20 February 2004.
  7. Brown, G. (2011) Speech made at the Institute for New Economic Thinking, Bretton Woods, New Hampshire, 11 April 2011.
  8. A Synopsis: Limits to Growth: The 30-Year Update
  9. See Is Global Collapse Imminent? by Dr. Graham Turner, Melbourne Sustainable Society Institute, 01 Aug 2014. See also Update to limits to growth, Comparing the World3 model with empirical data by Gaya Herrington for KPMG LLP, Los Angeles, California, July 2021.
  10. Daly, H. (1992) Steady State Economics. London: Earthscan, p. 88.
  11. Liu, E. and Hanauer, N. (2011) The Gardens of Democracy. Seattle: Sasquatch Books, pp. 11 and 87.
  12. See Beinhocker, E. (2012) ‘New economics, policy and politics’, in Dolphin, T. and Nash, D. (eds), Complex New World. London: Institute for Public Policy Research, pp. 142–144.
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