Starting with the characteristics of the electoral system, the Duverger agenda aims at predicting the expected average distribution of seats and votes among parties, their absolute number, and their deviation from proportional representation (RP). In the case of simple electoral systems, making such predictions has become possible for both the share of seats and for the likely lifespan of a government. Simple electoral systems are those using a standard RP formula or First-Past-the-Post, in which cases overall assembly size and constituency magnitude tell the whole story. However, work remains incomplete on both the share of votes and deviation from RP. Extending this work to more complex and mixed electoral systems also remains to be done.