Instead of direct impact measures, we realized, think tanks need to develop proxy impact measures, by searching for where their supply curve intersects with competitive demand in the marketplace of ideas. We had to identify and track the products that leaders consume at some cost to themselves and in a direct trade-off with alternatives. In isolation, each of these metrics is a single point of limited utility. But considered together, they paint a pointillistic picture that helps us assess the impact of our work.
Here are just two examples from the suite of proxy metrics we’ve come to use:
The most prestigious national newspapers each receive about 1,000 unsolicited op-ed submissions every week. The “market” for real estate on those papers’ opinion pages is unbelievably competitive, and editorial staffers ruthlessly reject everything except what they believe readers most need and want. That selectivity can reveal competitive demand for our product. Thus, although total op-eds written per year is just an output metric, the number of op-eds our scholars publish in a defined set of the most competitive outlets constitutes a viable proxy measure for impact. Though far from a catchall figure, this metric has one particularly useful aspect: The data is by definition public and thus allows comparison with peers and competitors. Every year to date, AEI has maintained a lead.
We do the same thing with congressional testimony. Most policy experts want to testify on the Hill, but they can’t just call up the Senate switchboard and get on the docket. The Senate calls you. So although nobody believes that public testimonies are the only way think tanks shape the debate, they do offer one useful angle for measuring impact. And again, it is helpful that everyone’s data is a matter of public record. When we initially analyzed these numbers, during the 110th Congress (2007–2009), AEI was in fourth place among think tanks in terms of congressional testimony. By the 111th Congress we were number one, and we’ve maintained that position ever since.