In a number of recent projects (see e.g here), I have been interested in the structure of the academic job market, how it is organised in different countries, and how it may shape the ideas that it produces (see here for a comparison of economists in the US and Germany). Something that we highlight in the latter paper is how concentrated and hierarchical the field of US economists is compared to Europe. Most top US economists are affiliated with a pretty small number of elite universities (Harvard, MIT, etc.). Is it different for other disciplines, for instance in political science? My hunch was that it isn’t.

I have just come across this paper by Kim and Grofman published in January 2019 on the “Political Science 400”, looking at the top-cited political scientists currently employed in US universities. The online appendix has some interesting data on these 400 top US political scientists, especially where they work now and where (and when) they got their PhD. This can give some interesting insights into the structure and hierarchies in US political science.

In the graph below, I have used this data to build a network of universities where each arrow represents a flow of political scientists in the top 400 linking the institution where they obtained their PhD (the source) and the institution where they worked in 2017 (the target). The size of the nodes represents the out-degree (the number of individuals who got their PhD from that institution) and the size of the arrows represents the number of academics

What does the data show? First, we can see a “core” of prestigious universities who are fairly closely connected with each other: Harvard, Stanford, Berkeley, Princeton, Columbia, University of Chigago, Yale. In fact the top-5 granting institutions alone (Harvard, Berkeley, Michigan, Yale and Stanford) account for 40% of all the political scientists in the top-400. Harvard alone supplies 49 of the 400 top political scientists. The structures that comes out is indeed hierarchical: the “inner circle” of universities at the top mostly recruit from within the top-circle, other universities outside the circle recruit from the top, but there is fairly little “upward” mobility: few top universities recruit people from outside the top circle. Finally, access to the upper tier of US political science (and probably the whole field) is not very open to academics with a foreign PhD: only 22 (5.5%) of the top-400 have a PhD from a foreign institution.