Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We axiomatize three different motivations for being concerned about intergenerational mobility: mobility as a description of movement, as an indication of equality of opportunity, and as an indication of equality of life chances. These three motivations are shown to be incompatible. None of the existing measures is acceptable as an indicator of equality of opportunity or equality of life chances. We propose two new measures of intergenerational mobility which more adequately reflect these concerns.