You shall not overkill: Substitution between means of group removal

This note places mass killing in a continuum of actions that a ruling power can take to remove an unwanted group from a society; that is, it views extermination as a means to an end, and it assumes that rulers are rational and will choose the combination of means that can achieve their goal at the minimum cost to themselves. The means are assimilation into the general society, physical removal from view (through either deportation within the country or exile from the country), and extermination. The note develops a simple model of input choice geared to cost minimization and then finds encouraging support from the historical evidence on communist regimes.