Monday, October 6, 2014
The thinking of economists began to ossify in the second half of the 19th century, at a time when the science of psychology was in its infancy. The model was thus consolidated at a time when our understanding of human behaviour was quite primitive.
Unfortunately, the past century of progress in psychology has revealed just how far astray are many of the economic model's assumptions about how humans tick. Although a minority of economists - "behavioural economists" - have sought to incorporate these findings into their thinking, the majority have ploughed on regardless. It keeps the maths simpler.
The model is often criticised, not least by me, for its key assumption that we are always "rational" - carefully calculating and self-interested - and never instinctive or emotional in the decisions we make, but there's another assumption that's equally unrealistic and likely to lead to wrong predictions about how we'll behave.
It's that consumers and businesses always act as isolated individuals in making their decisions, uninfluenced by the decisions those around them are making, except to the extent that the combined behaviour of others affects the prices the individual faces. In other words, the model's "unit of analysis" is the individual - the "representative consumer" or "representative firm".
In truth, humans are highly social animals and our behaviour is hugely influenced by those around us. We evolved to live in small groups, which has left us with a powerful - if often unconscious - motivation to fit in with the group and avoid being ostracised.
We feel most comfortable when we're doing what everyone else is doing; we feel distinctly uncomfortable when we're doing the opposite to everyone else. We feel great loyalty to the groups we belong to, and rivalry and suspicion towards groups we don't belong to.
This means humans - "economic agents" as economists say - are prone to herd behaviour. At the most innocuous level, this makes us heavily influenced by fashion. We like to wear what others are wearing, read what others are reading and watch the movies and TV shows that others are watching.
It's remarkable that the business world could be so conscious of the need to accommodate and, indeed, exploit our susceptibility to fashion while the economists seek to analyse our behaviour using a model that assumes it away.
More significantly, our tendency to herd behaviour affects the behaviour of markets - particularly financial markets - in ways that, though we've seen it happen many times before, almost invariably catch economists unawares.
It's our propensity for "group-think" that does most to explain booms and busts in the sharemarket, but also the upswings and downswings in the economy. We swing from overly optimistic to overly pessimistic, then back again, and we tend to all do it together.
A separate aspect of the model's exclusive focus on the individual is its overemphasis on competition and underemphasis on co-operation. It's actually the human animal's unmatched ability to co-operate in solving problems that has given our species its mastery over the planet.
Human behaviour is composed of competition and co-operation. We form co-operative groups so as to enhance their ability to compete with other groups. But the economists' model captures only one dimension of the process.
The classic example of group co-operation to facilitate competition is, of course, that bedrock of modern economies, the company. Companies - often very large, multinational companies - dominate our economy, but the model tells us nothing about what goes on inside them and economists don't have much to tell us about how the existence of big companies affects the behaviour of markets.
The final and perhaps most important twist that the economic model's focus on individuals imposes on economists' thinking is an inbuilt bias against intervention in markets by co-operation at its highest level, government.
The market of individual consumers and individual (tiny) firms is assumed to be self-sufficient and self-correcting, thus making intervention by government something alien and more likely to make things worse than better.
The reality, of course, is that governments not only need to "hold the ring" - provide the protection of property rights and legal enforcement of contracts - they also need to impose rules that protect the market, and the rest of us, from the consequences of its own herd-driven excesses.