Ideas about the links between education, income and democracy are at the heart of what social scientists in the middle of the last century termed the “modernisation hypothesis”. One of its most famous proponents, Seymour Lipset, wrote in 1959 that “education presumably broadens men’s outlooks, enables them to understand the need for norms of tolerance, restrains them from adhering to extremist and monistic doctrines, and increases their capacity to make rational electoral choices.”
Since then plenty of economists and political scientists have looked for statistical evidence of a causal link between education and democratisation. Many have pointed to the strong correlation that exists between levels of education and measures like the pluralism of party politics and the existence of civil liberties (see left-hand chart). The patterns are similar when you look at income and democracy. There are outliers, of course—until recently, many Arab countries managed to combine energy-based wealth and decent education with undemocratic political systems. But some deduce from the overall picture that as China and other authoritarian states get more educated and richer, their people will agitate for greater political freedom, culminating in a shift to a more democratic form of government.
This apparently reasonable intuition is shakier than it seems. Critics of the hypothesis point out that correlation is hardly causation. The general trend over the past half-century may have been towards rising living standards, a wider spread of basic education and more democracy, but it is entirely possible that this is being driven by another variable. Even if the correlation were not spurious, it would be difficult to know which way causation ran. Does more education lead to greater democracy? Or are more democratic countries better at educating their citizens?