The Washington Post Federal Page reports on some research here: "It turns out that the career managers, on average, do a better job of running federal agencies than the political appointees do. So says a 41-page study by political scientist David E. Lewis of the Woodrow Wilson School of Public and International Affairs."
It compares OMB's ratings of programs run by career bureaucrats versus those run by political appointees and finds the former do better. (Trigger the fireworks, let's celebrate.)
However, as an ever-cautious bureaucrat, some skepticism is in order--Dr. Lewis may be comparing apples and oranges. For example, in USDA circa 1970, the Soil Conservation Service was run by careerists, Farmers Home administration was run by politicos. But the programs were different--SCS was more "scientific" and less controversial than the loan-making functions of FmHA. I'd guess that there's a high correlation between "careerist" managers and "scientific" (i.e., not politically controversial) programs. That raises the issue of whether it's easier in some sense to run a program where the outcomes are more knowable and can be judged by clearer criteria. The question answers itself.
Political appointees run agencies that the public as a whole does not trust. The decline of trust in government over the past 40 years has been paralleled by an increase in the number of politically led agencies.
So while the work of Dr. Lewis is welcome, I'm going to save my fireworks.