The January 12, 2009 issue of The New Yorker includes a well-written and in some ways inspiring article by Elizabeth Kolbert, profiling Van Jones, founder and president of Green for All. In the article, "Greening the Ghetto: Can a Remedy Serve for Both Global Warming and Poverty," Kolbert includes the following passage:
When I presented Jones's arguments to Robert Stavins, a professor of business and government at Harvard who studies the economics of environmental regulation, he offered the following analogy: "Let's say I want to have a dinner party. It's important that I cook dinner, and I'd also like to take a shower before the guests arrive. You might think, Well, it would be really efficient for me to cook dinner in the shower. But it turns out that if I try that I'm not going to get very clean and it's not going to be a very good dinner. And that is an illustration of the fact that it is not always best to try to address two challenges with what in the policy world we call a single policy instrument."
That brief quote generated a considerable amount of commentary in the blogosphere, much of it negative, and some of it downright hostile. This surprised me, because I didn't consider the proposition to be controversial, and I had chosen my words carefully, simply stating that "it is not always best to try to address two challenges with ... a single policy instrument." Two activities -- each with a sensible purpose -- can be very effective if done separately, but sometimes combining them means that one does a poor job with one, the other, or even both.
In the policy world, such dual-purpose policy instruments are sometimes a good, even great idea (gas taxes are an example), but other times, they are not. Whether trying to kill two birds with one stone makes sense depends upon the proximity of the birds, the weapon being used, and the accuracy of the stone-thrower. In the real world of important policy challenges -- such as environmental degradation and economic recession -- these are empirical questions and need to be examined case by case, which was my point in the brief quote. Since my further explanation of this point in the green jobs context (in an interview that lasted 30 to 60 minutes -- I don't recall) did not find its way into Ms. Kolbert's article (no fault of hers -- she had plenty of sources, plenty of material, and limited space), let me provide that explanation here.