Knowing and Making

Eric Falkenstein has an interesting post  which highlights some of the problems in the study of behavioural economics (in this case, behavioural finance). I have to agree with his premise, though my conclusions are a bit different. I've just reread some of Nudge  and am partway through Animal Spirits . Both books cheerlead for the behavioural cause - though in each case, one author - Thaler and Shiller respectively - seem to be much more closely associated with it than the other - Sunstein and Akerlof. However both books exemplify the problem that Falkenstein identifies. The field is full of effects without explanations. You can easily list a whole string of cognitive biases which can be easily demonstrated - I show the effect directly to audiences in presentations, by running a price anchoring experiment. But the behaviourists rarely seem to propose a good underlying model of how these effects arise. Having just completed another book, The Making of an Economics, Redux , I can see...

If you have clicked onto this article just from reading the title, then I may disappoint you slightly. I am not (yet) going to propound a behavioural theory of money, though I think there's one coming in the future. But I will point to a couple of results which may indicate where to get one. The first is a quote from John Moore and Nobu Kiyotaki of LSE, in the beautifully titled lecture Evil Is The Root Of All Money . "Money is the medium of exchange. Notice that for this argument to hold together, there has to be a set of mutually-sustaining beliefs, stretching off to infinity. I was willing to hold money yesterday because I believed the dentist would accept it today. She is willing to hold money today because she believes someone else will accept it tomorrow. And so on. If there were a known end-point to history, the entire structure of beliefs would collapse back from the end." This, as they point out, is the conventional view among microeconomists about the existence ...

I was very pleased to see the FT's leader today, " Maths and markets ". It robustly defends mathematicians from responsibility for the financial crisis (an odd assertion of Lord Turner's). Not only that, but it also points to an interesting behavioural question: But financial mathematics has been underfunded, given its economic importance, and both private and public sectors must commission more research in the field. For instance, we need to know more about the way human psychology affects market models – and about the scenarios in which models break down. The need to blend psychology and mathematics is not often recognised, and it's good to see the FT coming around to it. I absolutely agree with this, needless to say - both Intellectual Business and Inon continue to work on mathematical modelling of human decision-making and working out its consequences at the market and macroeconomic level. That sentence does contain a subtle kicker at the end: " the sc...