Foreign Policy magazine just put out a ranking of the world’s think tanks. The methodology that FP used was a survey of “hundreds of scholars and experts.”
The problem with this type of ranking is that it is more of a popularity measure than a measure of resource efficiency. A think tank with a lot of money is going to do a lot of work, some of it presumably of high quality and some that will in turn have impact on its agenda. But how do we determine which of these institutions is good at using resources to turn them into influence? David Roodman of the 15th-ranked Center for Global Development points out that if the rankings were based on productivity, his outfit would do even better.
So are the higher ranked outfits more productive or is it just name recognition?
Using the data from Foreign Policy I created a scatterplot with the Y-axis as the rank and the X-axis as the last annual budget in millions. IF (big IF!) we accept that the survey of the experts is a legitimate way of ranking policy impact AND that the difference in impact between each rank is linear, then we can measure resource efficiency in generating impact.
In this first scatterplot we include RAND which has a huge budget.

The graph outlines that bigger budgets bring you a higher rank. The trendline is negative because a higher rank is actually a lower number (e.g. the highest rank is 1, the lowest 15.) Relative to RAND, places like Brookings, Carnegie, and CFR look pretty resource efficient in that they get significant acclaim at a much lower cost. Unfortunately, the linear regression has a terrible fit (low R-squared) and annual budget is a statistically insignificant coefficient. The bottom line is that RAND is such a quirky and important outlier, that you can’t really say the comparison yields any reliable insight.
If we exclude RAND given its unique military ties and projects, we get a much more insightful outcome to the linear regression.

While the equation does not explain a majority of the differences in how the think tanks were ranked, it has much higher r-squared and the annual budget coefficient is statistically significant (p-value of 0.01 through Excel.) Without RAND, Brookings and most of the think tanks exhibit similar resource efficiency. The bigger their budgets, the higher their rank. Thus, they are all mostly equally efficient at translating monetary resources into a good ranking. Carnegie stands out as having a very high ranking at a noticeably lower cost. On the other extreme, the National Bureau of Economic Research and Human Rights Watch appear inefficient. Ro0dman’s CGD is about where you’d expect given the data set.
There are obviously MANY MANY flaws to this way of analyzing efficiency. My intent is to demonstrate how to think about efficiency in the social sector and particularly in the policy advocacy space. I agree with Roodman that we need to take productivity into account when ranking think tanks and also agree that we need to start prototyping approaches to figuring that out.




