Henry Farrell writes:
Via Cosma Shalizi, this is a nice tool for mapping the relationship between donations from energy companies and politicians in Presidential, House and Senatorial elections. . . . Why is it that there appears to be so little literature out there on this kind of network? Is it the difficulty of establishing causal relationships (although surely this would invalidate whole swathes of US political science if this standard were applied rigorously)? Is it difficulties in gathering the relevant data (Cosma notes that gathering it and cleaning it up is surprisingly hard)? The perceived publication practices of major US journals? I’m genuinely puzzled as to the reason why there’s this gap in the literature. Both comparativists (Jerry Easter) and international relations scholars (Charli Carpenter) have published well regarded articles in the major journals of their field on the importance of networks in domestic and international settings. So why not Americanist political scientists?
In trying to answer this question, I think it’s important to separate two aspects of the above research: network analysis as a general statistical/social-science research method as applied to Americna politics, and the analysis of political contributions in particular.
In social science as a whole, networks have become very trendy–and I pretty much think that’s a good trend. There are some roadblocks in applying these ideas to the study of public opinion and voting, however, since we’re talking about a network of 250 million adults where the average person knows only 750 other Americans. You can get this sort of data from surveys but it’s hard to know what to make of it. Tian Zheng, Tom DiPrete, Julien Teitler, and I have been involved in a research project estimating the segregation of Democrats and Republicans in social networks, and we collected data specially for our study. Still, the analysis is difficult, just at the technical level of building a statistical model for what we’ve got. It’s no surprise that a lot more work has been done on networks in Congress. This isn’t the part of American politics that I study but it counts, right? But, getting back to public opinion and voting: networks are clearly important but they’re hard to study given the inherent sparseness of the data.
Moving to research on political contribution networks, I wonder if one reason you don’t hear much about it is that this sort of work is politically marginalized, as it’s associated with left-wing critiques of the political system, rather than more traditional representations of American politics as being generally representative of public opinion. For example, I don’t know that Thomas Ferguson has formally used network analysis, but he and his collaborators have done lots of work tracking down campaign contributions (and I’m not talking about Vin Scully here). I agree with Henry that political donations would be a natural place for network analysis, since many of the major contributors have clear enough links that sparseness is less of an issue.