Recoding the regions of the European Social Survey into the NUTS 1 regional classification. Illustration: regional indicators of intergenerational solidarity

In recent years, a number of standardized and comparable social surveys have become available for a wide range of European countries, for example the International Social Survey Program, the European Social Survey, and the World Values Survey. At the same time, and probably to some extent as a result of it, techniques of multilevel analysis have grown more popular in the social sciences.
To fight the potential problems with using the country as the contextual level in multilevel analysis, we contemplated a way to carry out multilevel research with subnational regions, nested within countries, defining the basic contextual level. We argue that multilevel analysis will gain in substantive scope as well as in statistical power if the EU's regional statistics could be linked with the data from social surveys and combined in the same analysis. Yet, in order to make that possible, the regional classification of the surveys has to be harmonized with the regional classification used in official EU statistics.
The aim of this exercise, therefore, is to harmonize the subnational regional classification used in one social survey, in particular the European Social Survey (ESS), with the regional classification used by Eurostat, i.e. the NUTS classification. This report provides a technical note on recoding process of regional classification variables from ESS into variables with NUTS 1 level regions, followed by the illustration of how such variables can be used. This is presented on the basis of the study on intergenerational solidarity.