Within- and between-department variability in individual productivity: the case of economics

In the social sciences, university departments are the governance units where the demand for and the supply of researchers interact. As a first step towards a formal model of this process, this paper investigates the characteristics of productivity distributions in a unique dataset consisting of 2,530 faculty members with at least one publication who were working in the 81 top world Economics departments in 2007. Individual productivity is measured in two ways: as the number of publications up to 2007, and as a quality index that weights differently the articles published in four journal equivalent classes. The academic age of individuals, measured as the number of years since obtaining a Ph.D. up to 2007, is used to measure productivity per year. Independently of the two productivity measures, and both before and after age normalization, the five main findings of the paper are the following. Firstly, individuals within each department have very different productivities. Secondly, there is not a single pattern of productivity inequality and skewness at the department level. On the contrary, productivity distributions are very different across departments. Thirdly, the effect on overall productivity inequality of differences in productivity distributions between departments is greater than the analogous effect in other contexts. Fourth, to a large extent, this effect on overall productivity inequality is accounted for by scale factors well captured by departments’ mean productivities. Fifth, this high degree of departmental heterogeneity is found to be compatible with greater homogeneity across the members of a partition of the sample into seven countries and a residual category