The presence of a state is one of the most reliable historical predictors of social and
economic development. In this article, we complete the coding of an extant indicator of state
presence from 3500 BCE forward for almost all but the smallest countries of the world today.
We outline a theoretical framework where accumulated state experience increases aggregate
productivity in individual countries but where newer or relatively inexperienced states can
reach a higher productivity maximum by learning from the experience of older states. The
predicted pattern of comparative development is tested in an empirical analysis where we
introduce our extended state history variable. Our key finding is that the current level of
economic development across countries has a hump-shaped relationship with accumulated
state history.

• State history and economic development: evidence from six millennia