Structural equivalence in multilevel research

In cross-cultural research, there is an increasing interest in the comparison of constructs at different levels of aggregation, such as the use of individualism-collectivism at the individual and country levels. A procedure is described for establishing structural equivalence (i.e., similarity of psychological meaning) at various levels of aggregation based on exploratory factor analysis. A construct shows structural equivalence across aggregation levels if its factor structure is invariant across levels. The procedure was applied to the Postmaterialism scale of the World Values Survey. The similarity of postmaterialism at the individual and country levels could not be unambiguously demonstrated; a likely reason is that the concept does not have an identical meaning in countries with low and high gross national products.