The book "Harmonising Demographic and Socio-Economic Variables for Cross-National Comparative Survey Research" offers a comprehensive analysis of harmonization techniques used in survey research to align national systems of categories and definitions, enabling comparisons across countries and cultures. It is aimed at researchers who wish to collect internationally comparable data and presents tools that are significant for these purposes. The focus is on seven key demographic and socio-economic variables: education, occupation, income, employment status, private households, ethnicity, and family. These variables are essential for any survey and provide deep insights into the social structures and national organization of societies. The book highlights the challenges associated with the comparability of national education systems and the definition of concepts such as "private household," emphasizing the need to harmonize these concepts rather than simply translate them.