International comparisons of data on expenditure on education use purchasing power parities for currency conversion and adjustment for price differences between countries to allow for volume comparisons. The resulting indicators are commonly interpreted as differences between countries in input volumes to the education sector-teachers, materials, buildings, and so forth. This article shows, however, that the ranking of countries is vulnerable to the choice of spatial deflator for converting data in national currencies to internationally comparable indicators. If the one adjusts for differences in the prices of inputs in the education sectors, the indicator significantly overestimates the input volume in countries with high teacher wages, such as Switzerland and Germany.