Everyone has heard the nightmarish stats on how much kids cost. According to the feds, a couple making between $57,000 and $98,000 a year, before taxes, will cough up $222,360 raising a child to age 17. And many moms and dads feel that childcare and kid-chauffering duties seriously limit their career opportunities. But economist Bryan Caplan, author of the new book Selfish Reasons To Have More Kids, says there's no persuasive reason to devote so much time and money to parenting. Here, a brief guide to his contrarian take:

So... we're spending too much on kids?
"In a nutshell," says Sierra Black at Strollerderby, "Caplan believes that parents are 'overcharging' themselves for their children." By committing to intense tactics like attachment parenting, which requires moms to carry newborns non-stop and respond to their every desire, they're unnecessarily robbing themselves of time. Parents also feel obligated to spend a fortune on lessons of every kind, and an endless stream of educational videos and toys.

And all that expensive attention is really unnecessary?
Yes. Caplan says the bottom line is that nature — the kids' genes — mostly determines who they'll be; the power of nurture, he says, is minimal. Research on twins and adopted children shows that kids raised by highly educated parents with big vocabularies, for example, tend to know more words when they're tiny. But by the time they reach age 12, "the effect of enriched upbringing on vocabulary was barely visible," Caplan says in The New York Times.

So what should parents do?
Save your money, relax, and don't be afraid to have more kids. In Caplan's view, says Brian Doherty at Reason, "it's perfectly OK and harmless to rely on 'electronic babysitters' such as TV and video games, as well, to make parenting less costly on you." He wants parents to focus instead in enjoying the experience of parenthood, and watching their kids grow up. "Most people think that raising decent kids requires decades of unpleasant sacrifices," Caplan tells the Times. "No wonder they’re tempted to keep their families small — or remain childless."

What do the critics say?
Caplan is reading too much into the twin studies, says Tyler Cowen at Marginal Revolution. The same kid will turn out vastly different if raised by Amish, or Chinese-American, or orthodox Jewish parents; nurture likely has more influence than Caplan cares to admit.

Sources: Infographic Insights, Strollerderby, NY Times, Reason, Marginal Revolution, Wall St. Journal (2)