Review of the Opposition Movements and Groups dataset

The Opposition Movements and Groups (OMG) dataset is a global dataset on large-scale political mobilization campaigns that challenge or preserve the core features of a political regime or a polity's territorial integrity. The dataset spans the period from 1789 to 2019 and covers 151 countries. The unit of analysis in OMG is the campaign phase. A campaign is defined as a series of temporally contiguous, organized collective actions pursuing a political objective related to regime change, institutional reform, leadership removal or preservation, or territorial autonomy or secession.