“Why did the autonomous city-state die?” asks political-economic historian David Stasavage in a new American Political Science Review article. He finds that new autonomous city-states enjoyed higher population growth rates than nonautonomous city-states, up to 108 years. After that point, their population growth was lower than that of nonautonomous city-states. His argument is that the fusion of political and guild power within autonomous city-states at first promoted growth, but as technology changed came to suppress growth, relative to more “inclusive” institutions.
A better interpretation is that political institutions deteriorate with age, the law of political entropy. After all, if changing technology meant that constant institutions became less efficient, then population growth in autonomous city-states should vary by century, not by age of the city-state. Since in fact population growth varies by age of the city-state, we have evidence that the institutions were not constant: they became less efficient.
HT: Chris Blattman