“The only function of economic forecasting,” wrote the great American economist John Kenneth Galbraith, “is to make astrology look respectable.” It is characteristic of Erica Thompson’s sprightly and highly original new book on the uses and abuses of mathematical modelling that she dares to turn Galbraith’s verdict on its head. The medieval practice of casting horoscopes, she shows in one typically engaging section that embodies her most important themes, has a surprising amount to teach us about the modern practice of using models to guide policy.
The topic is an exceptionally important and timely one. The Covid-19 pandemic, the climate crisis, and turbulence in financial markets are just three examples of how fundamental mathematical modelling has become to decision-making in many areas of modern life.
