The Downside of Economic Imperialism

The fourth comment on this Scatterplot post* reminded me of a post I had long meant to write, but was too lazy to. So, here comes the monster, complete with scholarly references.

The term economic imperialism refers to the fact that economists often study topics outside the classical realm of economics, such as crime and the family. Pretty much single-handedly invented by Gary Becker, and popularized by Steven Levitt and Stephen Dubner in their book Freakonomics, it is now all the rage among young economists. If I am informed correctly, an upstarting American economist should steer well clear of unemployment and economic development and rather study AIDS or basketball if she wants to make a career.

Many sociologists loathe economists muscling in on their turf, but I'm all up for it. If you want to accumulate knowledge, a fresh perspective is welcome; also, the average economist seems to be better at statistics than the average sociologist. (I still remember a professor of mine almost bragging about how he flunked his entry-level statistics course twice as a student.)

As pointed out in the aforementioned comment, the problem is that when coming up with an "original" topic, economists often - not always - seem to assume that they are the first people to ever have thought of this issue, which is often incorrect.

As a handy illustration comes a 2006 paper by Steven Levitt disciple Todd Kendall on the availability of pornography (via the internet) and rape. The classical feminist view is, of course, that pornography causes rape, but apparently Richard Posner has submitted that masturbating to pornographic depictions is a substitute for rape. Note that this presupposes that sexual gratification is a motivtion for rape, which some (cf. Pinker 2002: 359-62), but not all (cf. Freese 2000: 159-71) feminists dispute.

Kendall provides a state-level analysis that controls for other covariates of crime and estimates that a 10% increase in internet availability decreases rapes by 7.4%.

At the time the paper came out, a blogger calling himself Falstaff pointed out that in all likelihood, the regression analysis is plagued by collinearity problems because Kendall includes both a measure of internet access and a measure of the no. of computers in households as independent variables. To add, another reason to suspect collinearity is that he includes both %unemployed and %below the poverty line. As is bad practice in the social sciences, Kendall provides netiher a table of correlations between independent variables nor formal collinearity statistics. Strangely, Kendall (2006: 24) notes that collinearity "may explain some counterintuitive results" and then goes on to completely forget about that.

That alone would suffice to render his results completely uninterpretable. More to the point of this post, Kendall does not control for a number of well-established covariates of crime, such as %black (or racial heterogeneity), economic inequality, and measures of family disruption (see the meta-analysis by Pratt 2001: Table 5.2 in particular). (Note. If you include these, you want to perform a factor analysis first, so as not to introduce even worse collinearity problems.)

This is unsurprising given that Kendall seems to be largely ignorant of the literature. There are literally hundreds of macro-level analyses of crime of the type that Kendall provides (cf. Pratt 2001); by my count, he cites four. More specifically, he also seems to be unaware of the literature about associations of gender inequality (e.g., Austin and Kim 2000, Whaley 2001) or sex ratios (e.g., Barber 2004) with rape.

As a consequence, we learn nothing about Kendall's interesting question from his paper.

Bottom line: Economic Imperialism: Yes, please. Careful study of the literature: Yes, please.

References

Austin, Roy L. and Young S. Kim, 2000: "A Cross-National Examination of the Relationship between Gender Equality and Official Rape Rates." International Journal of Offender Therapy and Comparative Criminology 44: 204-21

Barber, Nigel, 2004: "Single Parenthood as a Predictor of Cross-National Variation in Violent Crime." Cross-Cultural Research 38: 343-58

Freese, Jeremy, 2000: What Should Sociology Do about Darwin? Evalutating Some Potential Contributions of Sociobiology and Evolutionary Psychology to Sociology. Indiana University: Diss.

Kendall, Todd, 2006: "Pornography, Rape, and the Internet." Clemson University: Working Paper.

Pinker, Steven, 2002: The Blank Slate: The Modern Denial of Human Nature. New York et al.: Viking

Pratt, Travis C., 2001: Assessing the Relative Effects of Macro-Level Predictors of Crime: A Meta-Analysis. University of Cincinatti: Diss.

Whaley, Rachel Bridges, 2001: "The Paradoxical Relationship between Gender Inequality and Rape: Toward a Refined Theory." Gender and Society 15: 531-55

*It seems that stating that "I'm not becoming a regular" at Scatterplot has made me read the blog more regularly. Talk about a suicidal prophecy.

Addendum: Given that it's Lotsa Links to Scatterplot Week here at the CoR, I might as well add that in my unbiased opinion, this post qualifies me for being a contributor to soc2econ. Next week: Lots of links to hot pictures of Natalie Portman. Promised!