Sarah Nequam sends along a link to this paper by Andrew Eggers and Jens Hainmueller:

While the role of money in policymaking is a central question in political economy research, surprisingly little attention has been given to the rents politicians actually derive from politics. We use both matching and a regression discontinuity design to analyze an original dataset on the estates of recently deceased British politicians. We find that serving in Parliament roughly doubled the wealth at death of Conservative MPs but had no discernible effect on the wealth of Labour MPs. We argue that Conservative MPs profited from office in a lax regulatory environment by using their political positions to obtain outside work as directors, consultants, and lobbyists, both while in office and after retirement. Our results are consistent with anecdotal evidence on MPs’ outside financial dealings but suggest that the magnitude of Conservatives’ financial gains from office was larger than has been appreciated.

I don’t know enough to know what else has been done in this area but it looks interesting. I think that in political science we’re usually more interested in politicians’ funders than their personal finances–the usual view, which I assume is true, is that the amount of money a politician might personally derive from office is minor compared to the flow of government funds whose dispersal he controls. (Here I’m talking about typical elected politicians in developed countries, not politician-businessmen like Berlusconi or people like Mobuto or King Leopold who pretty much own entire countries.) So, my first inclination is to think of findings like those of Eggers and Hainmueller as interesting but not crucial to political understanding. But I could be wrong on this, and it certainly seems worth looking into. And the authors seem to have done an impressive amount of work here.

Some minor comments:

– I hate the term “rents” when it’s not actually applied to rent. It just seems like a jargony thing to me, and I’d rather just say directly what’s being studied.

– Doesn’t their word processor have that “£” symbol? That seems cleaner than “GBP.”

– Tables 1, 2, 3, 4, 5, 6, 7, and 8 should be graphs. (Sorry, I had to say that. But I mean it.)

– Getting more specific on the tables: In table 8, they should rescale the predictors so the coefficients are directly interpretable (then you won’t have numbers like “2e-4” to try to figure out). You could use coefplot() to display it and the other tables of regression coefficients. In table 7, are the mean values of age, years as MP, years as former MP all really integers to 2 decimal places? I guess it could happen, but maybe there was some rounding? I wouldn’t mind except for those pesky “.00″‘s.

– Figures 5 and 6 are nice. They tell the story right away. Only a couple things need to be done to make these better. First, I’d use smaller symbols (dots, rather than squares and circles) and remove the legend, instead labeling the x-axis appropriately so it’s clear that everything below 0 is losing and everything above 0 is winning. (You don’t need separate symbols–position tells all here–and if you use a dark color for your points, then little dots will be visible.) Second, I’d do it all in black and white. I mean, color is fine, keep it if you want, but it’s not necessary. Third, do log-base-10 rather than log. log10 is more directly interpretable. Better still, just label the y-axis with actual money values (10 thousand, 100 thousand, etc); i.e., use a log scale but put unlogged round numbers on the axes). Finally, make the graph s a little more squat and then you can stack Figures 5 and 6 together as one figure that tells your whole story. (You can just put the word “Conservative” or “Labour” inside each graph on the upper left.)