Our tax code is stuck in the Middle Ages. The Internal Revenue Code (“the Code”), codified at 26 U.S.C., uses the concepts of addition, subtraction, multiplication, and division, as one might expect of a tax code. But, disdaining the 1500s invention of the elementary math symbols ‘+,’ ‘–,’ ‘×,’ and ‘÷,’ the Code instead uses complicated English constructions such as “any amount of X which bears the same ratio to that amount as Y bears to Z.”
I propose that we use these elementary math symbols in our tax laws. To see whether this would increase the laws’ legibility, I conducted a preregistered, randomized, controlled trial involving 161 participants. One group received the actual Code, the other, a translation using math symbols. Both groups were asked to solve the same two Code-based tax problems. For the first problem, use of the translation with math symbols increased answer accuracy from 25% to 70%. For the second problem, answer accuracy increased from 11% to 50%.
This result, I argue, can be extrapolated to the broader population and to the Code as a whole, confirming the plausible intuition that math symbols would increase the understandability of the Code. I then argue that this would be a good thing, answering various objections along the way, with a particular appeal to the rule of law and the spirit of democracy. People ought to be able to understand the laws that govern them.