Fighting Legal Innumeracy
Cheng, Edward K.
An old joke quips that lawyers go to law school precisely because they never liked math or were never good at math – and that therefore medical school (or these days, Wall Street) was not an option. While this tired joke may have a kernel of truth, I want to suggest that we should be very wary of internalizing it. Numeracy is a fundamental skill for any intelligent, engaged participant in society, and we lawyers ignore it at our peril. The term “innumeracy” was coined by Douglas Hofstadter in a 1982 article in Scientific American and perhaps made famous by John Allen Paulos.1 In his book, Paulos observes that while readers frequently condemn grammatical errors, wild mathematical ones often pass undetected. If this observation is true for anybody, it is definitely true for lawyers. Playing gotcha with typos is practically the official sport of the bench and bar. Yet, lawyers and courts notoriously make incorrect numerical calculations – sometimes caught, sometimes not – but generally without the same snarky rebukes.The primary focus of Hoftstadter and Paulos, however, is on the inability of the public to grapple with numbers. Accordingly, they stress the importance of estimation and orders of magnitude. For example, just how big is a billion dollars, or a trillion dollars? Or more trivially – though not so for aspiring management consultants – how many ping-pong balls will fit into a backyard swimming pool? I want to recast the numeracy problem to be a bit more lawcentric. For lawyers, numeracy should be less about numbers per se and more about statistical inference or how to interpret and understand scientific or social scientific studies.