This paper introduces a new dataset on regional authority in 42 democracies for 1950-2006 and formulates five hypotheses. First, an S-curve effect describing a logistic association between the population of a country and its regional authority. Secondly, a heteroskedasticity effect, in which the variance in regional authority among larger countries is greater than that among smaller countries. Thirdly, an identity effect, in which the allocation of authority to a jurisdiction is influenced by the relative strength of a population's identity to the community encompassed by the jurisdiction. Fourthly, a democracy effect, which leads democracies to have higher levels of regional authority than dictatorships. Fifthly, an integration effect, which removes a potential economic cost on regionalization by providing a transnational frame for economic exchange.