Fear, greed, fairness, imagination and finance

I’ve thoroughly enjoyed reading Adaptive Markets: Financial Evolution at the Speed of Thought by Andrew Lo. I should say that, apart from being a distinguished MIT finance professor and the co-author of the classic A Non-Random Walk Down Wall Street, Andrew is an old friend. But this should not put off any readers. This new book will become another essential read for anybody interested in financial markets.

The book aims to do what ultimately all of economics must do, and situate economic decisions and behaviour in the context of our biology and evolutionary history. Behavioural economics and finance have gone some way toward this in introducing the now-familiar heuristics such as loss aversion and framing effects, and herding is a familiar phenomenon in finance models. The issue with these has been how if at all they relate to rational choice models and the Efficient Markets Hypothesis. The Adaptive Markets Hypothesis is a synthesis, proposing that context makes the difference, and when conditions are sufficiently stable for long enough, financial markets are efficient. Otherwise, fear, greed, fairness, imagination – the characteristics evolution has given the human brain – kick in.

The opening chapter starts with a powerful demonstration of the potential efficiency of markets: after the Space Shuttle Challenger tragically exploded on 28 January 1986, a five month inquiry pinned the blame on a part, the O-ring, manufactured by one of four contractors, Morton Thiokol. Yet on the day of the accident, the share price of Morton Thiokol plummeted – the markets knew the company was to blame almost immediately, without the expert verdict: “Somehow the stock market in 1986 was able to aggregate all the information about the Challenger accident within minutes, come up with the correct conclusion and apply it to the assets of the company.”  The decline in its market capitalization – about $200m – was  almost exactly equal to the damages, settlement and reduced future cash flow, a later study found.

But often, of course, financial markets are all too obviously sometimes not efficient. The intellectual challenge is to figure out when they are in which mode. The book voyages through neuroscience, psychology, evolutionary biology and AI to try to answer this. The Adaptive Markets Hypothesis reverses the conventional framing: rather than thinking about a rational benchmark with a set of psychological quirks sometimes kicking in, we are a collection of quirks, but sometimes we can get beyond the heuristics to rational choice.

Frustratingly, although perhaps inevitably, there is no neat list of conditions for being in efficient rather than non-efficient mode: it depends, in particular on having had enough time in stable conditions to learn from experience. But Andrew does hold out hope for the prospects of being able to make better investment decisions – with socially useful outcomes – and being able to manage financial markets better so events like the 2008 crisis are far less likely to recur. In line with the Adaptive Markets perspective, he argues for treating financial markets as an ecosystem (so the interconnections are front of mind), using AI techniques to monitor markets and adjust regulatory instruments such as cyclical buffers. There is an interesting section on the role of technology in finance, including HFT, a technological arms race being one of the predictions of the Adaptive Markets Hypothesis. Currently, he is exploring ideas from biology such as immune responses and ecosystem management techniques. He also recommends introducing a body similar to the National Transportation Safety Board that would analyse market crashes and make recommendations for regulatory change. (One thing not spelled out here is whether this would have to be a global body.)

The book is a thoroughly interesting and enjoyable read. It is not technical, the explanations are super-clear, and there is some excellent story telling. Andrew recounts how in 1986 he and his co-author Craig MacKinlay, presenting at the NBER the work that turned into A Non-Random Walk Down Wall Street, were savaged by discussants from the world of academic finance. Since then, the academic community’s faith in the Efficient Markets Hypothesis has wavered significantly, but it is still the benchmark – as the book says, it takes a theory to beat a theory. I find the Adaptive Markets Hypothesis a persuasive theory, but then I firmly believe economics must be consistent with what we learn about ourselves from the other human sciences. I guess the test will come in the shape of how widely market participants themselves embrace it.41CpHzPtybL



Not the smartest animals

The title of Frans de Waal’s latest book is a rhetorical question: Are We Smart Enough to Know How Smart Animals Are? I thoroughly enjoyed reading it. De Waal’s deep knowledge shines through every sentence, as does his delight in all the creatures (especially other primates) he has spent his career studying. The book is about the evolution of cognition and emotion in animals (including humans). It particularly debunks Skinner’s behaviourism – mental processes as a black box, but manipulable using reward and punishment. (This of course the approach behind the present fashion for behavioural economics, a fashion I find troubling because some of its enthusiasts do so clearly see themselves as omniscient scientists ordering society for the better by manipulating the choices of their less intelligent subjects.)

I learned a lot from the book, including that the elephant brain is the one with the most neurons (about 3 times as many as we do). The neural differences between humans and other primates are not sufficient to make us unique in all aspects (although we clearly are in some, notably language). De Waal argues we should assume continuity, a spectrum of cognitive abilities between different animals, rather than sharp and wide distinctions. He notes that psychology is moving to accept this assumption, but the social sciences tend to assume human discontinuity – “But what does it mean to be human?” he reports social scientists asking him. “I usually answer with the iceberg metaphor, according to which there is a vast mass of cognitive, emotional and behavioural similarities between us and our primate kin. But there is also a tip containing a few dozen differences. The natural sciences try to come to grips with the whole iceberg, whereas the rest of academia is happy to stare at the tip.”

The scientific project must therefore be to develop a unitary theory of different cognitions, how cognition operates in general, and then in the case of each particular species. The book emphasises two important contributors: sense perceptions (is vision the most important to the species? or hearing, or smell?); and social relations (is it a species with strict social hierarchies, like chimpanzees, or solitary, like the octopus?) “Cognition and perception cannot be separated… they go hand in hand,” he writes. (Interesting to reflect on what this means for AI. The question is not so much what androids dream of as what they see or hear.)

To crown a wonderful book, it ends with a quotation from David Hume: “Tis from the resemblance of the external actions of animals to those we ourselves perform, that we judget their internal likewise to resemble ours; and the same principle of reasoning, carried one step farther, will make us conclude that since our internal actions resemble each other, the causes, from which they are derived, must also be resembling. When any hypothesis, therefore, is advanced to explain a mental operation, which is common to men and beasts, we must apply the same hypothesis to both.” As Hume summed it up, “No truth appears to me more evident than that beasts are endowed with thought and reason as well as men.”



Economics and evolutionary science

I recommend this Evonomics post about economics post-2008, and the kind of re-evaluation that’s been going on among economists, citing somewhat critically Noah Smith and also Dani Rodrik’s excellent . Author David Sloan Wilson complains: “All good, but there is something missing from the internet links that I just provided—any discussion of evolutionary theory.”

[amazon_image id=”0393246418″ link=”true” target=”_blank” size=”medium” ]Economics Rules: The Rights and Wrongs of the Dismal Science[/amazon_image]

I couldn’t resist preening a little, for my 2007/2010 book , has a whole chapter, Murderous Apes and Entrepreneurs, about the importance of the links between economics and evolutionary biology. This also forms one strand of my 2012 Tanner Lectures. In other words, I wholly agree with the argument of the Evonomics post, but thhink there has been a little bit more progress than it acknowledges.

Of course, formal evolutionary theorising is not part of the conventional economics mainstream, although it has some distinguished practitioners; but having said that informally it widely informs much business economics. There are also some leading economists who have been thinking about the overlap between economics and evolution. The ‘murderous apes’ of the chapter title was inspired by Paul Seabright’s brilliant ; Wilson cites Robert Frank’s . There is also an active strand of research on complexity theory, which and among others have written about.

[amazon_image id=”B004XCFI2Q” link=”true” target=”_blank” size=”medium” ]The Soulful Science: What Economists Really Do and Why It Matters[/amazon_image] [amazon_image id=”0691146462″ link=”true” target=”_blank” size=”medium” ]The Company of Strangers: A Natural History of Economic Life[/amazon_image] [amazon_image id=”B008W4ASGC” link=”true” target=”_blank” size=”medium” ]The Darwin Economy: Liberty, Competition, and the Common Good[/amazon_image]

Economics will have to be consistent with what we learn about human behaviour and decisions from other human sciences, not just the other social sciences, but also evolutionary biology, cognitive science and psychology.


Time for the next techno-enviro-social paradigm?

On this week’s flights I read by Ian Morris. I thoroughly enjoyed Morris’s big book, , a grand sweep of economic and social history in the vein of (, ) Jared Diamond. This new book is a series of essays based on his 2012 Tanner Lectures at Princeton, with comments/criticisms and a response. So it’s much shorter and less detailed than the previous one, although a very good and enjoyable read nonetheless.

[amazon_image id=”0691160392″ link=”true” target=”_blank” size=”medium” ]Foragers, Farmers, and Fossil Fuels: How Human Values Evolve (The University Center for Human Values Series)[/amazon_image]

Morris comes across here as a sort of meets Jared Diamond. In a nutshell, his argument is that humanity has grown better at using the prevailing energy technology to acquire more kilocalories of energy for use, up to a ceiling. At that ceiling, a new energy basis for society evolves, importantly affecting population density and the size of human social groups, and replaces the previous social/technical paradigm. Domestication of grains and animals enabled farming to replace foraging. The extraction of fossil fuels and their harnessing as steam power led to industrial societies in place of agrarian ones.

Each of these three paradigms involves a different kind of social relations: egalitarian in foraging societies because co-operation is necessary for hunting and gathering, and nobody has a lot of property; hierarchical ones in agrarian societies because some people accumulate property to be defended, and a biological division of labour between the sexes emerges too; and industrial ones more egalitarian with respect to politics and gender but tolerant of wealth inequality. There has been little if any biological evolution among humans – and through the millennia the same basic characteristics (or even values) such as the capacity for love, a sense of fairness etc, exist – but there has been cultural evolution. Specifically, values evolve, being shaped by interaction with the physical, social and intellectual environment. Is it acceptable to treat women as chattels or to have slaves? Do animals have the right to humane treatment? Does marital fidelity matter? These kinds of values have changed significantly.

Although it seems highly plausible that the material and technical basis of a society plays an important part in shaping its higher level values, and that population density and the size of social groups will be important, there is something that feels a bit deterministic about Morris’s argument. It may be that at this short length the arguments become caricatures, with less scope for nuance, because the four critiques of the argument aren’t all that convincing either.

The book has lots of facts, always appealing to me. For instance, did you know the Royal Navy’s West Africa Squadron had intercepted and freed 150,000 Africans being shipped across the Atlantic to the US between banning slave trading in 1807 and the outbreak of the US Civil War in 1865?

It ends rather gloomily, pointing out that the big transitions he identfies – from foraging to farming to fossil fuels – occurred when successful societies hit the “hard ceiling of what was possible given their stage of energy capture and found themselves taking part in a natural experiment….. More often than not, people failed to revolutionize their energy capture and suffered Malthusian collapses.”

Perhaps, he muses with unseemly cheer, that’s about to happen to us unless we can solve the climate change issues. So that’s our choice: a catastrophic collapse of civilization, or a new techno-enviro-social paradigm.


Shiny models versus human nature

It’s been one of those weeks – three days with meetings from morning to night. So I’m only half way through  by Michael Lewis, even though he writes like a dream and it’s a pleasure to read.

Meanwhile, I was distracting myself this morning with this interview with E.O.Wilson. Why did he become a biologist? Not much else to do growing up in Alabama, he says here, apart from looking closely at ants.

I’ve not read many of his books, including the famous/notorious ; but I was inspired by  (1998) and enjoyed .

[amazon_image id=”034911112X” link=”true” target=”_blank” size=”medium” ]Consilience: The Unity of Knowledge[/amazon_image]

My notes from reading it in 1999, nicely scrawled on by a 2 year old, have the following quotations:

“Social scientists as a whole have paid little attention to the foundations of human nature and they have almost no interest in its deep origins.” (This obviously does not refer to the earliest social scientists such as David Hume, John Locke, Adam Smith, and is becoming less true of at least some of today’s social scientists.)

“Thanks to science and technology, access to factual knowledge of all kinds is rising exponentially while dropping in unit cost. Soon it will be available everywhere on television and computer screens. What then? The answer is clear: Synthesis. We are drawing in information while starving for wisdom. The world henceforth will be run by synthesizers, people able to put together the right information and the right time, think critically about it and make important choices wisely.” (Right analysis but optimistic conclusions? Not much overt sign of more wisdom in action.)

And on economic models: “Their appeal is in the chrome and the roar of the engine, not the velocity or destination.” Vroom, vroom.