Economists are slowly revealing the weaknesses of their ‘rational’ theories

Associate Professor Martin O’Brien, of the University of Wollongong’s Sydney Business School, commissioned a longitudinal survey (looking at the same people over time) of about 1830 employees and about 240 owner-managers or employers, dividing the workers between those on awards and a control group of those on enterprise agreements (and so not directly affected).

The economists’ standard, “neo-classical” model of the way demand and supply interact to determine the market price, with movements in the price feeding back to influence the quantity that buyers demand and the quantity sellers want to supply, does predict that a fall in the price of Sunday labour will lead employers to demand more of it.

So what did the survey find? It could find no effect on employment in the retail and hospitality sectors. This is consistent with a growing body of mainly American empirical evidence that, contrary to neo-classical theory, increases in minimum wages have little effect on employment.

But here’s an interesting twist: a majority of employers reported not making the reduction in penalty rates and a majority of employees reported not receiving any reduction.

One explanation for this is that employers didn’t pass on the cuts because they valued staff loyalty and commitment. If so, this fits with the judgment of many labour economists that the relationship between a firm and its workers is far more nuanced than can be captured by the neo-classical assumption that price is the only motivator.

An alternative explanation, however, is that those employers didn’t cut the Sunday penalty rate because they weren’t paying it in the first place.

Turning to the laboratory experiment, it tests the much more theoretical assumption that the behaviour of people engaged in economic activities is guided by their “rational expectations” about what will happen in the future.

It turns out that very few people display the rational expectations economists assume in their model-building.

Economists have come to care about what people expect to happen because this affects the way people behave, and so affects the future we get. In recent decades, many mathematical models of the macro economy have used the assumption that people form their beliefs about the future in a “rational” way to make the maths more rigorous.

By “rational” they mean that people respond to new information by immediately and fully adjusting their expectations – beliefs – about what will happen to prices, the economy’s growth or whatever. Which is a lovely idea, but how realistic is it?

Dr Timo Henckel, of the Research School of Economics at the Australian National University, Dr Gordon Menzies, of the University of Technology Sydney, and Professor Daniel Zizzo, of the University of Queensland, analysed the results of an experiment conducted by Professor Peter Moffatt, of the University of East Anglia, involving 245 students answering questions.

On receiving each piece of new information, the subjects had first to decide whether to adjust their beliefs and then, if so, by how much. The experimenters found that the subjects reacted very differently.

They found that, in general, people don’t update their beliefs with each new piece of information. And when they do, they tend not to adjust their beliefs by as much as they probably should. In other words, people display a kind of belief conservatism, holding on to a belief for longer than they should.

They found that this conservatism is explained to some extent by people’s inattention – they were distracted by other issues – and to some extent by the complexity of the issue: it was “cognitively taxing”.

It turns out that very few people – just 3 per cent of the subjects – display the rational expectations economists assume in their model-building. Most people’s behaviour, the authors say, is better described as “inferential expectations”.

Now, you may not be wildly surprised by these findings. But, in the academic world, common sense doesn’t get you far. You must be able to demonstrate things the academic way.

Loading

Even so, Henckel says that the responses of the experiment’s subjects extend to many parts of life, from the behaviour of investors in the share and other financial markets – this is how bubbles develop – to people’s political convictions, where they hold on to beliefs for far too long, ignoring much contrary evidence.

Indeed, inferential expectations apply even to scientists, who form a view of the world which they will revise or overturn only if there is overwhelming evidence to the contrary. So don’t expect economic modellers to abandon their convenient assumption of rational expectations any time soon.

Ross Gittins is the Herald’s economics editor.