The modernization thesis championed by political scientist Seymour Lipset argues that socioeconomic development would eventually lead to democratic development.
A new paper reevaluates the thesis and concludes:
Our overall conclusion is that the relationship between income and democracy and the widely-accepted modernization hypothesis need to be reevaluated, with much greater emphasis on the underlying factors affecting both variables and the political and economic development path of societies.
Our results indicate that countries have embarked upon different development paths, most likely at some critical junctures during their histories, and while some paths have led to democracy and prosperity, some others involved non-democracy and relative poverty.
Although democracy and prosperity coevolve along the virtuous development path, there is no evidence that income has a causal erect on democracy conditional on the development path.
Consequently, there is no reason to expect income changes over 5, 10 or even 20 year intervals observed during the post-war era to lead to signifcant changes in regimes above and beyond those experienced by the world as a whole.