This is an Appendix to the post, "How many parties does it take to run a government," addressing some common critiques of the methodology.
Some people have commented on the fact that the data drawn from the FEC records are not a random sample of government lawyers, and therefore the figures presented may not be representative of agency lawyers as a whole. That is true, but irrelevant. Contributors to political campaigns differ from non-contributors in three primary ways: (1) contributors tend to be more affluent, (2) contributors tend to have greater political interest, and (3) contributors tend to have greater partisan strength (e.g., Verba, Schlozman, and Brady 1995). This is especially true of people who contribute amounts large enough to trigger an obligation to report their contributions.
Thus, the figures reported may reflect the partisan preferences of more affluent and politically engaged lawyers within the agencies. It is hard to see how this undermines the conclusions about the partisan imbalance within the agencies. By far the most significant factor in determining whether one contributes to a political campaign and how much one contributes is family income (ibid.) So in order to significantly undermine the conclusions, we would have to assume that agency lawyers with lower incomes (or perhaps those less politically engaged) are much more likely to be Republicans. That seems unlikely, and therefore if anything the percentage of Democrat lawyers in the agencies is likely biased toward the low side, rather than toward the high side.
Many people have commented that the numbers in the tables are small relative to the total number of lawyers in the agencies, and that that somehow undermines the conclusions. First of all, to the extent the comment is addressed to statistical significance, it misunderstands high school statistics in ways too basic to warrant a discussion here. Second, the assertion that the numbers are small relative to the total number of lawyers isn’t really true. Take the IRS, for example. The table reports a total of about 50 contributors, whereas there may be as many as 2,000 lawyers in the agency (see the breakdowns here). But how many IRS lawyers listed their employer under “Treasury Department” or unspecified “Federal Government”? How many others contributed but fell below the threshold? Probably a significant number, so the numbers are almost certainly significantly higher than those listed.
Third, the percentage of government lawyers making reportable contributions is very, very large compared to the percentage in the public as a whole. Of the overall voting age population, only about 0.53% contribute $200 or more to political candidates, parties or PACs. If estimates are accurate that there are approximately 34,000 federal executive branch attorneys, then the 3,000 contributors in the database of agency lawyers suggest a rate of contribution much, much higher than the population as a whole. As mentioned above, higher rates of contribution follow from higher political engagement, and therefore it seems likely that agency lawyers are more politically engaged than the population as a whole.
Finally, some have wondered whether the results are driven by the fact that Barack Obama has been president for the past four years and therefore has had some significant influence over the composition of the agencies (e.g., political appointments). The data look almost exactly the same for the 2008 election (following 8 years of a Republican administration), and therefore such factors do not explain the results.