Women have for the first time inched past men among US citizens awarded doctorates, and nearly one in five doctorates is being earned by an ethnic or racial minority.
But the number of doctoral recipients overall in the US continues to slide, falling last year to just under 40,000, the smallest total in nearly a decade, according to a report by the University of Chicago-affiliated National Opinion Research Center.
The number of men who earn doctorates has dropped most quickly, down 15 per cent in the past five years, while the number of women has remained steady.
That has helped push the percentage of women receiving doctorates to 51 per cent of the total, a slim plurality.
If international doctoral recipients at US universities are included, men continue to outnumber women by 55 per cent to 45 per cent.
Women outnumber men by 56 per cent to 44 per cent among American undergraduates.
One reason for the overall decline in postgraduates earning doctorates is a difficult job market for PhDs compared with MBAs and other degree holders.
More than a quarter of those who received doctoral degrees last year had no prospects for professional employment or further study, the report says.
The biggest drops in doctoral programme enrolment are in the physical sciences and engineering.
International students now outnumber Americans in many US doctoral programmes. Nearly two-thirds of doctoral candidates at US universities in engineering, for example, were from other countries.
In all, international students account for 30 per cent of all doctoral recipients. The largest number comes from China with 2,644, followed by South Korea with 1,187, India with 838, Taiwan with 674 and Canada with 494.
Among American citizens receiving doctorates, 19 per cent came from ethnic and racial minorities, the largest percentage ever. The fields with the largest percentage of minorities were education, in which many black students earned degrees, and engineering, in which large numbers of Asians graduated.