Paola Giuliano and Nathan Nunn have a new working paper titled "The Transmission of Democracy: From the Village to the Nation-State." They argue:
We provide evidence on mechanisms, showing that past experience with local level democracy is associated with more supportive beliefs of national democracy today. This finding suggests the possibility that a tradition of village-level democracy may affect people’s attitudes about the appropriateness of democratic institutions, which in turn affect the stability of such institutions at the national level. In places where democratic institutions existed traditionally at the local level, it was natural for these institutions to be extended to the national level. National level democracy was more likely to be viewed as natural and legitimate by the population and was more likely to remain once implemented.
That sounds intutitive, but the authors use very interesting data:
The data, reported at the country, district, and grid-cell levels, are constructed by combining pre-industrial ethnographic information on over 100 ancestral characteristics for 1,265 ethnic groups with information on the current distribution of approximately 7,000 language groups reported at the grid-cell level. The database uses the languages and dialects spoken by current populations to construct measures of the characteristics of their ancestors.