Beware of Economists Peddling Elegant Models; Mathematics can be beguilingly elegant. It can also be dangerous when people mistake its elegance for truth.
April 9, 2013 Leave a comment
Beware of Economists Peddling Elegant Models
Mathematics can be beguilingly elegant. It can also be dangerous when people mistake its elegance for truth.
Albert Einstein’s theory of general relativity might be the best example of elegant math, capturing a wide range of subtle and surprising phenomena with remarkable simplicity. Step toward the practical, though, and physics moves quickly away from elegance to makeshift usefulness. There’s no pretty expression for the operation of a nuclear reactor, or for how air flows past the swept wings of an aircraft. Understanding demands ugly approximations, or brute-force simulation on a large computer.
In one very practical and consequential area, though, the allure of elegance has exercised a perverse and lasting influence. For several decades, economists have sought to express the way millions of people and companies interact in a handful of pretty equations.
The resulting mathematical structures, known as dynamic stochastic general equilibrium models, seek to reflect our messy reality without making too much actual contact with it. They assume that economic trends emerge from the decisions of only a few “representative” agents — one for households, one for firms, and so on. The agents are supposed to plan and act in a rational way, considering the probabilities of all possible futures and responding in an optimal way to unexpected shocks. Read more of this post









