Why do some countries have more inequality in terms of wealth or economic development, whether between big cities and urban areas, or just from region to region, than do other countries? I contend that in comparing the internals of one state/country to those of another, as much “all else equal” should be satisfied as possible. This can be accomplished to a large extent by resisting the error, or temptation, to make category mistakes, such as in comparing Singapore with China—a city-state to an empire-scale country—or in likening an E.U. state to the entire U.S. European scholars of comparative politics tend to make this category mistake, and non-European scholars are so used to the ideological aggrandizement that they do not typically even recognize the category mistake of treating an early-modern(rather than Medieval) kingdom-scale state of an empire-scale federal union as equivalent to another such union, as if a state in one such union, or a comparable sovereign state, were itself an empire-scale union. Resisting the ideologically-driven urge to begin with a category mistake would do wonders in studying comparative politics and political economy and providing more accurate and beneficial conclusions and recommendations.
The full essay is at "Economic Inequality."