The following piece was inspired by questions addressed to the NIGMS staff by a grantee concerning the number and sizes of grants awarded to female principal investigators. The answer to these questions and many others can be found in the publication, Women in NIH Extramural Grant Programs[1]. The document, which covers fiscal years 1984-1993, is the most recent publication on the subject. The following information about NIH grants to female principal investigators has been abstracted from that source, and references are given to the relevant sections of the publication.

Grant Applications

The percentage of applications to NIH from female principal investigators has increased steadily over the past decade from 16% of the total in 1984 to 22% in 1993. This increase, combined with the increase in the total number of applications to NIH, means the number of applications from women has increase by 73% from 2,821 in 1984 to 4,883 in 1993 (Section 2.1).

Grant Awards

The percentage of new and competing grant awards to female principal investigators has increased in parallel with the increase in percentage of applications, from 15% of total awards in 1984 to 21% in 1993. The number of new and competing grant awards to women has increased by 33% from 845 in 1984 to 1,123 in 1993 (Section 2.1).

Success Rates

Over the past decade, men have had somewhat higher success rates than women, but the gap has narrowed in recent years (Figure 1, Section 2.3). In 1993, the success rate for male applicants was 24.1%, while that for female applicants was 22.6%. Success rates for new (Type 1) applications have been similar for both groups over the decade, e.g., 17.8% for males and 18.1% for females in 1993. However, success rates for competing continuation (Type 2) applications have been higher for men, e.g., 40.2% for males and 38.4% for females in 1993 (Section 2.4).

Grant Length

There are no significant differences in the lengths of grants awarded to female or male principal investigators. The average grant length in both cases has been approximately 4 years since 1988 (Section 2.7).

Grant Size

The average size of grant awards to female investigators has been smaller than the average for male investigators (Figure 2, Section 2.6). This appears to result primarily from the fact that women generally request smaller amounts than men. The data show that the average percent reduction from direct costs requested for women has been less than that for men (Section 2.5 and Section 3.4).

Smaller budget requests from women and, thus, smaller grant sizes may be explained by the type of grant mechanism chosen (Section 2.8). For example, new female investigators are more likely than are their male colleagues to have been funded by the FIRST award mechanism, which provides a limited budget. The principal investigator of a program project grant, which is likely to be a large grant, is more likely to be a male rather than a female scientist.

Other factors which may contribute to the differences in grant size include the average age of female versus male principal investigators (Section 7.1) and the length of time a project has been funded. For example, Figure 3 (Section 7.3) shows the average dollar size of two types of awards (RO1s and R29s) by age group and gender. The differences between age-matched cohorts are small. This suggests that the largest factor contributing to differences in the average grant size by gender is the relative number of junior and senior investigators. Differences in the average grant size may be expected to shrink if the average age of female investigators (44.6 years in 1993) increases toward the average age of male investigators (46.6 years in 1993).


  1. To receive a copy of the publication contact the NIH Office of Extramural Outreach and Information Resources, 6701 Rockledge Dr., MSC 7910, Bethesda, Maryland, 20892-7901. Phone: 301-435-0714. The entire publication including figures can be accessed online.
Peter C. Preusch

Peter C. Preusch, Ph.D., National Institute of General Medical Sciences, National Institutes of Health, Bethesda, Maryland

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