The article examines how regional productivity differences in the European Union changed from 1975 to 2000. By analyzing data from 205 regions and 8 sectors, the researchers found that these disparities were influenced by differences in the types of industries in each region, as well as overall productivity gaps. They used a statistical method called Esteban's shift-share analysis to study these factors over time. The results show that both the types of industries in a region and the overall productivity levels play a role in regional productivity gaps, and that these factors are interconnected.