Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We correct the generalized version of the decomposition of multivariate inequality indices by attributes proposed by Abul Naga and Geoffard (Abul Naga, R. H. and Geoffard, P. Y., 2006. Decomposition of bivariate inequality indices by attributes. Economic Letters 90, pp. 362-367).