Comparing Demographic and Socio-Economic Variables Across Nations

Abstract

Equivalence of measures in comparative survey research crossing language, cultural or system barriers is inevitable: Equivalence is the only meaningful criterion if data is to be compared from one context to another. However, equivalence of measures does not necessarily mean that the measurement instruments used in different countries are all the same. Instead it is essential that they measure the same dimension. Thus, functional equivalence is more precisely what is required (Dogan and Pelassy 1990). Using functional equivalent measures in cross-national surveys ensures that data can be compared because the resulting measures reflect the same phenomenon, that is the social circumstances that one wants to measure (see Przeworki and Teune 1970: 39; Wendt-Hildebrandt, Hildebrandt and Krebs 1983: 46). This makes the criterion of functional equivalence to a validity criterion. But how is functional equivalence of measures achieved?