NIH has just released a whole slew of fascinating statistical data about grants awarded from 1998 through 2007. This is a 150+ slide Powerpoint deck with all kinds of grant award breakdowns catagorized by award type, awardee's career stage, awardee's sex, and all sorts of other interesting stuff. There is lots to discuss, but one of the first things to hit me when I skimmed the deck was one particular dramatic sex difference.
This graph breaks down the "success rate" over the last ten years for male and female applicants on "New" and "Continuing" R01 applications. R01's are the basic research project grants that form the backbone of funding for virtually every academic biomedical research lab in the nation. They average about $350,000 per year, and are sufficient to fund a research program staffed with three or four scientists. The annual success rate is the number of grants awarded that fiscal year divided by the number of applications. New applications seek funding for a new research project for the first four or five years, while continuing applications seek funding for a succeeding four or five year period of a research project that is reaching the end of a four-five year new (or previous continuing) award. PIs are free to apply for consecutive continuing awards for as long as they please, and many R01 grants have been received continuous funding for decades.
One noteworthy feature of the data is that continuing applications fare much better than new ones, with roughly double the success rate over the entire ten years. Another one is that the success rate for continuing applications has declined much more than that issues to discuss, but I want to focus on something else right now.
Applications for new R01s from men and women PIs have had identical success rates over the last ten years. However, applications for continuing support with male PIs have had consistently higher success rates over this period, although the difference seems to have declined a bit over the last five years. This is of tremendous significance career-wise, as successfully obtaining a continuing award is frequently a sine qua non for obtaining tenure and/or promotion, and it is also of tremendous significance for the long-term viability of a PI's laboratory regardless of career stage.
Why do the continuing R01 applications of men fare substantially better than those of women, while new applications do not? The review of a new application is based predominantly on the content of the application itself, while review of a continuing application also is heavily based on the extent to which the PI made good progress on achieving the goals of the preceding four-five year award.
Does the difference reflect operation of an explicit or implicit "old-boys' network" that systematically overvalues the progress of male PIs compared women? Or does it reflect objectively poorer progress of women on preceding awards compared to men? If the latter, what might be the reasons women make poorer progress?