Several arguments have been advanced to explain the surge in the democratizations around
the globe in the past three decades. Two of these explanations have attracted considerable
attention: the modernization hypothesis and the democratic domino theory. The
modernization hypothesis predicts that improved living standards in a country would drive a
democratic change, while the democratic domino theory posits that democratic demands in
one country could spill over into its neighbors through a “demonstration effect” leading to
better democratic conditions. A number of commentators have argued that the empirical
analysis of these explanations are based on too aggregate information (such as a higher per
capita income being the driver of the demand for higher democratic standards) such that the
mechanisms behind the democratizations cannot be well understood. On the other hand,
several other scholars have argued that the middle class plays an important role in driving the
demand for better democratic conditions. Nevertheless, most of these arguments have
remained formally untested with elaborate data and in rigorous regression framework.