A theory of the adverse effects of repression

Incumbents with the capacity to repress often stop well short of using it fully. We address this puzzle with a dynamic model of opposition behavior in regimes where contested elections coexist with systematic advantages for those in power. Opposition factions choose whether to become politically active under repression and, once active, whether to cooperate with the other active factions or pursue independent paths. Repression deters participation and shrinks the active opposition, but among the factions that remain it strengthens the incentive to cooperate, since victory ends repression and a smaller field makes a united front easier to sustain. At low and high levels of repression, entry incentives govern the size of the opposition and additional repression works as intended. At intermediate levels, the capacity to sustain cooperation governs it and additional repression enlarges the united front. When unity poses a sufficient threat and factions are sufficiently patient, the probability of staying in power is non-monotone in repression, and repressing as much as possible can be strictly suboptimal.