A simple model suggests that the ratio of men per woman suffering civilian punishment is proportional to the overall number of men per woman in civilian life. Scholars have considered variants of this simple model for nearly two centuries. It has come to be called “the stability of punishment hypothesis.”^ ^ ^ The most common variant of this hypothesis loosely states that the ratio of persons punished to total population is constant. Abstracting from the political process that defines crimes, abstracting from the bureaucratic process that administers justice, and abstracting from the social process that endorses the results, suppose that men and women have natural average propensities per person to suffer life-disposing punishment. Then a reduction in the ratio of men per woman in civilian life would produce a reduction in the ratio of men per woman suffering civilian punishment.
The stability of punishment hypothesis doesn’t account well for changes in the ratio of men to women suffering life-disposing punishment in civilian life. From 1805 to 1815, in the midst of the Napoleonic Wars, about 12% of U.K. men ages 15 to 39 served in the military. During World War I and World War II, about half of U.K. men of those ages served in the military. Despite this large difference in the extent of male mobilization, the ratio of men to women disposed in punishment in England and Wales fell similarly — by about a third — during the Napoleonic Wars, World War I, and World War II. Moreover, immediately after the Napoleonic Wars, the ratio of men to women banished temporarily more than quadrupled. After World War I, the ratio of men to women in prison returned to close to its pre-war level, but then trended upward so that during World War II it was nearly twice what it had been during World War I. These changes in the ratio of men to women in prison, as well as even larger ones across the whole of the twentieth century, occurred with little change in the ratio of men to women civilians.
The stability of punishment ignores many factors that affect punishment and the sex ratio of persons punished. Among other factors, the value of men in military service affects the social choice to dispose of men in punishment.