Parents don't matter that much

Update: Stephen Dubner emailed me, and pointed me to this much longer segment which has a lot of Bryan Caplan. So it seems like the omission that I perceived was more of an issue with the production and editing process and constraints of the Marketplace segment than anything else. End Update I play a lot of podcasts during the day as I go about my business on my iPod shuffle. One of them is Marketplace, which has a regular Freakonomics Radio segment, where Stephen Dubner "freaks" you out with incredible facts and analysis, often with a helping hand from Steven Levitt. With all due respect to Dubner and Levitt, this still has very pre-Lehman feel. Economics has "solved" the workings of the explicit market, so why not move on to other areas which are ripe for conquest by the "logic of life?" In any case this week's episode kind of ticked me off just a little. It started off with the observation that college educated women apparently put 22 hours weekly into childcare today, vs. 13 hours in the 1980s. I guess fewer latchkey kids and more "helicopter parents?" Dubner basically indicates that the reasoning behind this is many parents are in a "red queen" arms race to polish the c.v.'s of their children for selective universities. This makes qualitative sense, but can we explain an increase of 9 hours on average for the ~25% of women who are college educated on striving to make sure that their kids have Wesleyan as the safety school? Let's put our quantitative "thinking-caps" on "freakonomics" style. ~25% of adults have university degrees. ~80% of these have public university degrees, which are usually not too selective. Some of the ~20% are from not particularly elite religious colleges. So the subset of Americans who graduated from elite universities is actually not too large a number. You can include these as natural aspirants for the best spots for their children. And a proportion of the large remainder, I'd estimate ~90%, who didn't go to a university which required a great deal of stress and c.v. polishing would certainly strive and hope for better for their kids. But can this explain a 9 hour average rise among tens of millions of women? Doesn't seem to pass the smell test for me. I suspect there's a more general norm of shifting toward "high investment parenting" among the college educated cohorts. A second aspect of the Dubner piece for Marketplaceis that it totally doesn't clue the listener in to the reality that there's a huge behavior genetic literature which predates the interest of economics in the outcomes of parenting. ~10 years ago Judith Rich Harris came out with The Nurture Assumption, which reported the conventional finding that shared family environment only explains a small proportion of the variation in many behavioral outcomes within the population. The remainder is split between genes and "other environment" (which is a catchall category). More recently Bryan Caplan's Selfish Reasons to Have More Kids is steeped in Harris' work. It's gotten a lot of media exposure, so I was surprised that Dubner didn't mention Caplan. Instead he focused on Bruce Sacerdote at Dartmouth, who has done some research on outcomes for adoptive and biological children. His research in this area seems about right, judging from what I know about findings in behavior genetics. In other words, he's not a trail-blazer as much as a trail-tender. You can find a representative paper online, What happens when we randomly assign children to families?: