Dear Professor Mankiw,
I'm a resident at one of the Harvard hospitals. In the past couple of years I've had the chance to attend a number of inter-disciplinary seminars where you have statisticians, physicians, sociologists, anthropologists, epidemiologists and economists present. I've been impressed with what your discipline has to say: in virtually every seminar the economists are able to say something useful. Without inflating your ego, I've also noticed that the economists present better papers and are less likely to be caught off-guard in a seminar. They are also more likely to discover problems in the work of others. I've been trying to educate myself on the economic way of thinking by reading your blog, Freakonomics, and now, by slowly reading your textbook. But clearly, there's no substitute to being formally trained as one.
My question to you doesn't concern economics, but more its sociology. So feel free to ignore this email. At the seminar that I attend most often, I've noted the following:
1. The economists are the most aggressive people in the room. They have little patience for introductions, motivation, or "being nice". They want to spend the first 10 minutes trying to figure out the -entire- talk. If they're not happy, they tend to disengage. I will note that they're like this with each other also. Why are things this way in economics? There must be pluses and minuses to this way of interacting.
2. The economists are the only social-scientists in the room that are willing to argue with the statisticians. This could be that you are a more argumentative lot in the absence of substance, but also that you know something. I'm not qualified to tell who wins these disputes, but the statisticians seem to regard the economists with a high degree of regard. Why do you think that different disciplines view the importance of statistics differently?
3. There seems to no love lost between the economists and other social-sciences. Some of this has to do with the nature of interferce in the two disciplines: your colleagues are always concerned about confounders. Other disciplines like "to tell a story"; confounders are certainly of concern to them, but the issues of bi-directional causality, and omitted variables seem of second-order importance to them. As a physician, I share your colleagues view of the importance of "selection bias" (nice term, incidentally). Why do you think that different disciplines weight the role of confounders differently?
I posed these questions to one of the economists who regularly attends. His response (that I have permission to send to you) is as follows:
"In general, economists are smarter (we may be better looking too). It's fashionable not to say such things, but I will bet that if you look at the GRE and SAT scores of incoming PhD students at BU, Harvard and MIT, the average economist will sit at a higher percentile than the average (non-economist) social-scientist. Given that all the other disciplines are trying to recruit students with higher scores, I'm not willing to believe the explanation that these disciplines value other attributes that aren't measured in the GRE. Higher salaries in economics will tend to reinforce the "economists are smarter" phenomena. Smart people don't have the time waiting for the less-smart to catch up. If we can finish up the seminar in 10 minutes, then why not do it?
"To this ex ante advantage, add the role of superior and more rigorous training. Economics graduate school is not for slackers. It's like boot-camp in the Army. One example of this is that we are provided a much deeper understanding of statistics than every other social-science. Consequently, economists are able to publish in journals like JASA and the Annals of Statistics. No other social science is able to do this with the same frequency. This superior training, complemented by a generally higher comfort-level with mathematics is the principal reason for why economists will not shy away from statistics. I wish I had concrete evidence for my argument. At present, it's indirect evidence. But this "economics know more stats" argument is another reason for why we are more aggressive; we are able to see the strengths and weaknesses of a study faster than others who're not as fluent in the methods.
"Third, the set of advocates who are economists is quite small (I don't know if this reflects treatment or selection). In general, economists are more likely to make up their minds about whether a particular policy works based on theory or data. They may have priors, but not the the sort of "do-gooder"priors that advocates have. One of the reasons that economists are so aggressive with the non-economists is that we want to expose all the priors immediately. In my view, a lot of non-economics social science is straight advocacy. There is an important role for advocacy. It may influence policy more than science. But the nature of advocacy is to simplify and ignore nuance and confounding. But our (economists) beef with advocacy isn't its lack of nuance. We just get really upset when advocacy masquerades as science.
"Fourth, the economics job-market is just that -- a market. This means that the best people are more likely to be at the best programs. In other disciplines there are more "bad matches" (good people at bad places). What this means is that Harvard and MIT's economics departments are more likely to have the top economists than the Sociology Department is likely to have the top sociologists. This is important because what you're seeing at the Harvard seminars is an exchange between the best economists and not necessarily the best sociologists. The best sociologists may be able to clobber a mediocre economist."
I'm curious if you have some of your own observations to add to the above.