The weak or selective enforcement of parchment rules is a widely recognized problem in Latin American and developing states. In Chapter 1, Brinks, Levitsky, and Murillo theorize institutional weakness as the gap between the way social interactions should be structured by institutions and the actual way social interactions occur. We define enforcement as the set of actions that the state takes to reduce the size of that gap. Our point of departure is that enforcement is often uneven and therefore constitutes a key element of the politics of institutional weakness; when rules are enforced is equally, if not more, important than the content of the rules themselves.

In this chapter, we build an account of the political and societal determinants of enforcement to elucidate why and how weak institutions gain relevance and how strong institutions might, or might not, emerge from state action.