There are few systematically comparative cross-national studies of urban policy or service provision, partly because there is little in the way of empirical testable theory that might guide research and partly because the variety of institutional methods of providing and financing urban services in different nation states makes it difficult to carry out such comparisons. Urban systems theory, however, applies to all levels of urban society from local collections of towns and villages right up to the world system of cities. It also enables the development of empirically testable hypotheses linking the hierarchical system of cities with the level of expenditure on public services in metropolitan areas. An examination of data for seventy-six metropolitan regions in France, eighty-three in Italy, seventy-four in West Germany, and sixty-three in England and Wales supports the hypothesis. The article concludes that urban systems theory offers a theoretically well-developed and empirically powerful means of carrying out systematic cross-national comparative urban research.