Democracies have risen and fallen throughout the past 200 hundred years. But which characteristics are essential to a democracy and which are detrimental? One study, by economist Robert J. Barro, analyzed several factors including standard of living, urbanization, schooling, colonial history and religious affiliations. Barro found that:

• A relatively high standard of living is the single greatest determinant of a successful democracy.

• Having a large number of adherents to Protestant, Catholic and Hindu religions favors democracy, while having other eastern religions and Islam works against democracy.

• Being a former British or Spanish colony works in favor of democracy, while being a former French, Portuguese or other colony does not.

The study found that the positive effects of certain religions and colonial ties to Britain or Spain were reduced by a higher standard of living -- while the negative effects were not. In opposition to many theories, it found secondary education did not have a significant bearing on the success of a democracy. But a high level of primary schooling and having a large middle class were other factors that support democracy.

Source: Robert J. Barro, "Determinants of Democracy," Journal of Political Economy, December 1999.