We combine Acemoglu and Robinson’s model of the economic origins of democracy with Lohmann’s model of political mass protest. This allows us to analyse the economic causes of political regime change based on the microfoundations of revolution. We are able to derive conditions under which democracy arises peacefully, when it occurs only after a revolution and when oligarchy persists. We model these possibilities in a world of asymmetric information, where information cascades are possible, and where these cascades may involve errors in the sense that they make everyone worse off.