Social investment in Europe has primarily been measured by studying expenditure data from specific categories of social policy. This article argues that we need a more nuanced way of studying the presence of social investment, and develops a tool for measuring the ideational content of social investment in policy regulations. By operationalising three key policy dimensions of social investment; time, distribution and policy coherence, varying approaches of social investment are discerned, landing in the development of three ideal types: a strict social investment, a targeted social investment and a reactive social investment. To demonstrate its application, the social investment ideal-types are applied to cases of policies for unemployed youth in different European countries. The operationalisation and ideal types presented in this article provide a structure and nuance to the understanding and measuring of social investment, aiding in the further debate on its pros, cons and presence in European social policy.
