How Large Should the Strike Zone Be in "Three Strikes and You're Out" Sentencing Laws?

So-called “three strikes and you’re out” sentencing laws for criminal offenders have proliferated in the United States in the 1990s. The laws vary considerably in their definitions of what constitutes a “strike”. This paper adapts the classic Poisson Process model of criminal offending to investigate how varying sentence lengths and definitions of what constitutes a strike affect the effectiveness and cost-effectiveness of these sentencing laws. In particular, it asks whether by using different definitions for the first, second, and third strikes or different sentence lengths, one can make the resulting incarceration more “efficient” in the sense of incapacitating more crimes per cell-year served.