Dani Rodrik points us to The Comparative Constitutions Project, and it looks awesome:

The constitutions project involves the systematic collection, translation, digitization and coding of every constitution in the world since 1789.  It provides a wide array of comparative data on the formal institutional designs adopted by nations at different points in time.  It also provides valuable data on national contexts.

I’ve been reading the Federalist Papers to learn what different institutional structures have been suggested over the age, but this is even better.