Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This article is concerned with the awarding of PhDs in the USA and Canada in the post-WW II period, overall, by gender and major academic discipline. The effects of the explanatory variables lagged by 6 years, to allow for time-to-degree completion, are consistent with the model. Military conscription with educational exemptions and the Vietnam War increased male PhDs in the USA, but, as expected, had no effect for US females or in Canada. This suggests that the war and draft effect for US males were not reflecting other unmeasured North American effects. Government expenditures on research and development enhanced the PhD production, especially for males and in the physical sciences. The cyclical indicator, the adult male unemployment rate, has a weak positive effect for males in both the USA and Canada, suggesting that during the post-WW II period, the positive effect on graduate-level education of the reduced opportunity cost of time due to a recession was stronger than the negative wealth effect of the recession. Other variables the same, there has been an increase over time in the female receipts of the PhD, but there is no such trend for males. While males still receive more PhDs per year than females, the gender gap has decreased over time.