Mind the gap: Economics is catching up to the fact that we’re not always rational
Do Tube strikes make Londoners better off?
At first sight, the question is simply absurd. The answer is surely “no”.
But a paper in the Quarterly Journal of Economics comes to the opposite conclusion. Cambridge economist Shaun Larcom and his colleagues analysed the two-day strike of February 2014.
They obtained detailed travel information on nearly 100,000 commuters for days before, during, and after the strike.
A key feature of the strike is that nearly half the stations remained open. So most commuters could experiment with routes different to the ones they normally use.
The project may seem barking mad. But it investigates an important issue in economic theory.
Richard Thaler’s recent Nobel Prize for behavioural economics received a lot of publicity. Behavioural economics looks for examples of people making decisions in ways which deviate from those predicted by the rational choice model of economics.
A criticism from the mainstream is that deviations might indeed be observed at a point in time. But over time, they will disappear as people learn to be rational and make the best decision.
The Tube network remains the same for long periods of time. Commuters have many opportunities to learn about it. So almost all of them should use the quickest possible route to work. If someone has just moved jobs or homes, there may be a short period of adjustment. But everyone else ought to have learned the best way to travel.
Yet Larcom and his colleagues find that a significant fraction of London commuters fail to find their optimal routes. They come to this conclusion by comparing the journeys of the people in their data set before and after the strike.
Of course, for many journeys the best route is trivially easy to discover. If you live in Richmond and work in Hammersmith, there is only the District Line. Other journeys have more options. Larcom notes that there are 13 potential ways to travel between Waterloo and King’s Cross.
The authors point out that many decisions faced by consumers are more complex and less repetitive than the commuter problem they analyse. So, in an excellent example of jargon, they state that “our estimate of suboptimal habits may be a lower bound to the problem in other contexts”.
In other words, systematic and persistent deviations from rational choice are an important feature of the real world.
Economists of course like to value everything, and there is a standard way of valuing time. The academics estimate that the time gains subsequently achieved by those who switched routes outweighed the time losses incurred by everyone else during the strike. So Londoners were better off as a result of the strike.
Bizarre though it may seem, the article is a good example of how economics is becoming much more empirical when thinking about individuals’ behaviour and less reliant on pure theory.