Comparative ageing research: a flourishing field in need of theoretical cultivation.

Comparative ageing research is a flourishing field, partly because of European funding in this area. Comparing different societies and cultures seems especially fruitful for the analysis of societal and cultural factors in development over the life course. From a nomothetic perspective, the aim of comparisons is the search for similarities and communalities in different societies and cultures; from an idiographic perspective, researchers are looking for societal and cultural specificity and distinctiveness. However, the potentials of comparative ageing research are not fully realized for the time being. In many cases, there is little theorizing as to whether there should be differences (or similarities) in ageing processes across countries, societies, or cultures. This paper discusses theoretical aims and ambitions of comparative ageing research in general. Comparative theories are sketched which could serve as a basis for comparative ageing research, and ageing theories are discussed which could be modified to be used in comparative research. The rationale of comparative ageing research is described and illustrated through empirical examples. Epistemological and methodological pitfalls (problems of conceptual, operational, functional, and measurement equivalence) are a substantial obstacle to comparative ageing research. Hence, merits and limitations of comparative designs and sampling procedures are considered.