Are Doctors Less Likely to Smoke? Do Economists Invest Better? Are Political Scientists More Likely to Vote?

And do ethicists behave better? Regular visitors will know that the last question is one I've been struggling with for a while. But what about the three in the title? If it turns out, as most philosophers seem to think, that ethicists don't behave morally better than non-ethicists of similar social background, is that simply part of a general phenomenon -- a general disconnection between professional stance and personal behavior? Or is it something more specific to ethics?

Before reading on, pause a bit. What do you think? Are doctors less likely to smoke than non-doctors of similar social background? Are economists more astute with their money?

Here's what I've found so far: Doctors are, it seems, substantially less likely to smoke. In U.S. and Australian surveys (the two countries that have the most literature on this), they typically come in dead last in smoking, or very nearly so, among long lists of professions. For example, David J. Lee et al. (2007) find that workers in U.S. "health diagnosing occupations" report smoking at rates of 5-6% in the last 20 years, compared to 26-28% of the general population. "Teachers, librarians, and counselors", the occupational category with the second-lowest rate, were twice as likely to report smoking as were doctors: 11-13%.

One complication is that these surveys are based largely (not entirely) on self-report, and doctors may be more embarrassed to report smoking than are teachers. It seems unlikely to me that embarrassment alone would explain such a large effect, but it would be nice to see a confirmatory study not based on self-report.

Nor is it just in the U.S. and Australia that doctors appear to smoke less. Recently, studies in China and the Ukraine have found similar results. Studies of doctors' other health behaviors (getting shots, mammograms, checkups, etc.) are more mixed, but are confounded by differences in availability and the temptation to self-diagnose and self-treat.

I've had more trouble finding data on whether economists invest better. However, Charlotte Christiansen, a Danish economist, shared with me a forthcoming study that suggests that Danish economists are at least more likely to hold stocks than comparably educated peers in other professions. Given the standard view in portfolio theory that most investors err in being insufficiently invested in stocks (often simply failing to "invest" at all, leaving their money in bank accounts and money market funds), and that almost everyone of middle-class means should own some stocks, Christiansen's results suggest that at least economists aren't falling quite as much into that mistake. About 42% of those with an education in economics owned stocks, compared to no more than 27% for any of the other 10 educational groups.

I haven't yet managed to find any data on whether professors of political science are more likely to vote, but I'm considering looking into that issue myself. Whether someone has voted is publicly available information in California. I could, for example, compare lists of ethics professors, non-ethicist philosophers, political science professors, and a control group of other professors, and see which groups are more likely to execute this civic duty. Any guesses?