Economist Bryan Caplan: Kids Can Be Cheaper Than You Think…

…so maybe you want more of them than you think you want. He makes the case for this controversial proposition at length in his fascinating and well-argued new book Selfish Reasons to Have More Kids: Why Being a Great Parent is Less Work and More Fun Than You Think.

He makes a much shorter version of the case over at the New York Times's "Economix" blog today. One of his central contentions is, roughly, that since research shows that the effect of upbringing specificially as opposed to genes on how kids turn out in the long run is very small, Western parents especially are often wasting their time with much of their high-cost efforts in raising up their kids right. Some excerpts from the Times interview touching on this stuff:

Q. … On the one hand, genes clearly matter. On the other, young children of college graduates, for instance, know hundreds and hundreds more words on average than young children of high-school dropouts. That difference is not mostly genetic. 

You seem to have a different sense of the research. You write, "Adoption and twin research provides strong evidence that parents barely affect their children's prospects." What's the brief version of how you try to persuade skeptics like me?

Mr. Caplan: ……what does the twin and adoption data say? Language fits a standard pattern. Consistent with your skepticism, upbringing has a noticeable effect on the vocabulary of young children. But as children mature, this effect largely fades away. The Colorado Adoption Project found, for example, that 2-year-olds adopted by high-vocabulary parents had noticeably larger vocabularies. But as the kids grew up, their vocabulary scores looked more and more like their biological parents'. By age 12, the effect of enriched upbringing on vocabulary was barely visible.

Admittedly, there's a sense in which upbringing is all-important: If a baby is raised by wolves, he won't know any words. (There's also a sense in which genes are all-important: If you had wolf DNA, you wouldn't know any words either.) But twin and adoption research focuses on questions that are much more relevant for parents: how your child will turn out if you switch to another parenting style…..

Mr. Caplan: Happiness researchers consistently find that people with kids are less happy than otherwise identical people without. The result holds up, but there's a lot more to the story. First of all, the "depressing" effect of kids, while consistent, is small. Married-with-kids is far happier than single-without-kids, but happiness researchers rarely bemoan the plight of childless singles. Second, kids do extremely well by another plausible standard: customer satisfaction. Over 90 percent of parents say they'd make the same decision if they had a "do over," and over two-thirds of childless adults over 40 say they wish they had kids when they had their chance.

The finding that parents are slightly less happy is actually one of the main motivating facts behind my book. The problem isn't that kids "ruin their parents' lives," but that parents need a little more tranquility and time for themselves. That's why the evidence from twin and adoption research is such good news for parents: Parents can make their lives better today without making their kids' lives worse tomorrow.

A few of my favorite specific suggestions:

1. While parents often lose sleep for years, getting kids to sleep through the night is not hard. Real experiments confirm that the Ferber method — let your baby cry in his crib for 10 minutes, briefly comfort him, leave, repeat — works wonders.

2. Improving kids' behavior isn't hard either. Experiments confirm that clear, consistent, mild discipline — like putting kids in the "Naughty Corner" — works even on difficult kids. The problem is that if parents stop imposing discipline, kids soon revert to their old tricks….

Caplan says: it's perfectly OK and harmless to your kids to rely on "electronic babysitters" such as TV and video games as well to make parenting less costly on you. Which leads to the core of his economists argument: if you make having kids less costly on you, you'll likely want more of them.

Mr. Caplan:  ….Most people think that raising decent kids requires decades of unpleasant sacrifices. No wonder they're tempted to keep their families small — or remain childless. The good news of twin and adoption research is that sacrifice is overrated. Parents are "overcharging" themselves for their kids. And what do economics and common sense tell you to do when prices turn out to be lower than you thought? Buy more. Stock up. Tell your friends.

….Instead of fruitlessly playing Pygmalion, focus on enjoying your journey together. Raise your kids with kindness and respect. Find common interests. Use discipline not to teach lifelong lessons, but to persuade your kids to treat you and others decently here and now. If you use these strategies, parenting and bigger families really are a lot of fun.

Caplan's last controversial book, The Myth of the Rational Voter, was the basis of a classic Reason magazine cover story back in 2007.