So you can greatly increase the chances of your children voting the way you do, going to your church and thinking fondly of you. But that’s about it. “Instead of thinking of children as lumps of clay for parents to mold, we should think of them as plastic that flexes in response to pressure—and pops back to its original shape once the pressure is released.”

That is Mr. Caplan’s first bit of good news. The second is that if you are a reasonably well-adjusted and happy person, your kids probably will be, too. All of which means that parents don’t need to invest nearly as much time and energy in parenting as they think they need to. “You can have a better life and a bigger family,” he says, “if you admit that your kids’ future is not in your hands.”

With the economics out of the way, Mr. Caplan tries coaxing parents into taking their hands off the wheel. “The first step to happier parenting,” he observes, “is to abandon ‘recreation’ enjoyed by neither parent nor child.” Your daughter hates ballet class and you hate schlepping her there? Drop it. Planning to travel hundreds of miles for a family vacation that will make everyone miserable? Try a “staycation” instead. Get take-out food, he urges, and hire a housekeeper. But above all get a nanny—even if she doesn’t speak fluent English or have a driver’s license. Your life will be easier, and your kids won’t be any worse off—they may even turn out better, since you’ll be setting a better example by being less anxious.