A recent post on Rock Talk presented data on the amount of funding as a function of PI age group. These data were not presented in a terribly informative way but a file was available for downloading and Michael Hendricks normalized the data by the number of PIs in age group to reveal more interesting trends, discussed at Drugmonkey.
The downloadable data includes a breakdown of Direct and Total Costs. I have been looking for such data over a longer period than the last couple of year and thought I would take a look. Below is a plot of the Effective Indirect Cost Rate ((Total Costs-Direct Costs)/Direct Costs) for the overall data set.
The Effective Rate drops from 44.2% to a low of 37.2% in 2012 before rising slightly over the past two years. These values are all somewhat lower than I anticipated based on my previous analysis on R01s.
To try to gain some insight, I looked at these data as a function of PI age group.
The differences between the age groups quite substantial and surprising. For the lowest three PI age groups, the Effective Rate is relatively constant around 47%, consistent with my previous R01 indirect cost analysis. For the older PI age groups, the Effective Rate falls steadily from 1998 to 2012, reaching rates as low as 27.5% for PIs 61-65 in 2012.
I certainly do not understand what underlies these trends, but differences in mechanisms could certainly be involved. It may be that mechanisms as as U01s for larger efforts could be important. As always, it would be best to see data broken down by mechanism to facilitate accurate interpretation.
Any other thoughts on these data are most welcome.