Kai Ryssdal: Time now for a little Freakonomics Radio. It's that moment every couple of weeks where we talk to Stephen Dubner, the co-author of the books and the blog of the same name, about the hidden side of everything. Dubner, good to talk to you.

Stephen Dubner: Hey you too, Kai, happy summer. My kids are already out of school, how about yours?

Ryssdal: Two more days.

Dubner: All right, so I'm curious what a guy like you puts your kids through during the summer. I sent you a little checklist, I was just curious. Want to take a look at that?

Ryssdal: Yeah, it's not a bad list. So museums -- no, we will not be doing museums because that makes me do work. There will be some baseball, there will be some singing lessons, there will be tennis and language, and lots of swimming, because it's L.A. in the summertime.

Dubner: That's pretty busy. Now, you are not alone, I'm happy to say, in spending a lot of time with your kids. Check out this message from Valerie Ramey, who's an economist at the University of California, San Diego, who looked into how modern parents are spending their time.

Valerie Ramey: In the 1980s, the average young college-educated mother spent 13 hours per week on childcare. Now, it's 22 hours a week. Now what's interesting is over this same time period, the wages of college-educated women have really increased. So the opportunity cost of time has increased at the same time they've decided to spend more time taking care of their children.

Ryssdal: So that's, like 13 to 22, is like nine hours -- 75ish percent? What are the mothers doing with that time, though, Dubner?

Dubner: Well it's interesting. You've got a lot of opportunities, you've got a lot of work. And what a lot of these high-end mothers are doing is chauffeuring their kids around to things like music lessons and fencing lessons and horseback riding. Valerie Ramey -- some of it's for fun, obviously -- but Valerie Ramey calls it "the rugrat race." Her argument is that kids have to work harder to get into good colleges these days, and therefore their parents enable them by pushing them toward all these extracurricular activities that are going to look good on a college application.

Ryssdal: Which, you know, on the face of it sounds reasonable, but really is kind of ridiculous and painful.

Dubner: You know, I think it has to do with parents thinking of their children as investment vehicles a little bit, right? That's what we think about: we want to invest in them so that they will pay off -- whether for themselves or for us.

Let me let you hear from a different economist, his name is Bruce Sacerdote, he's at Dartmouth. He wanted to know how much this kind of activist-parenting -- if you want to call it that -- actually pays off. And one way to measure this, especially if you're talking about educational achievement -- which is what parents probably care about the most -- is to look at adoption studies, where you can actually measure the impact that a family, that the parents, will have on a kid.

Ryssdal: So what's his thesis, that kids adopted into, I guess, high-education homes will be more likely to go to college, is that the deal?

Dubner: Exactly right. If parents are so important, then parents can take an adopted kid who might otherwise not have gone to college, and that kid will become college material. So Sacerdote sliced and diced a lot of good data and he did find parental influence.

Bruce Sacerdote: But it's not quite as big as I expected to find.

Ryssdal: All right, so quantify for me: how big is not so big?

Dubner: If you're a child who's adopted into a high-education family -- that is where the parents both went to college -- you are about 16 percentage points more likely to go to college than a kid who gets adopted into a low-education family. So that sounds pretty good, OK?

Until you compare that to the rate for biological kids from high-education families, who are about 75 percentage points more likely to go to college than biological kids from low-education families. So on the one hand, this is a little dispiriting for parents. We don't seem to have as much influence as we might think. On the other hand, in a weird way, it kind of takes some of the pressure off, right? At least it did for Bruce Sacerdote.

Sacerdote: This notion that genes are really important and that kids are hard-wired to do certain things, I think understanding that did help me relax and not worry so much that I was going "screw them up" in some terrible way.

Ryssdal: OK, so that's a good thought. But I have two observations to make. The first, as an adoptive parent -- and maybe this says more about me than about Sacerdote's numbers -- but it is 100 percent likely that my adopted daughter is going to go to college, just like my biological boys. So I guess that probably talks about me. But the other one is: there is more to measuring the success of parenting and the resulting children than where they to go college, or even if they go to college at all, Dubner.

Dubner: Absolutely. There's love and happiness and satisfaction -- all that good stuff. But here's the thing: the data seem to suggest that a lot of parents who get wrapped up in activist-parenting, who push their kids toward accomplishment, might actually make themselves unhappy as parents and might end up sacrificing some of that good stuff. So that's really the balance. If you want to go off the balance, you might even consider the opposite end of the spectrum, the style embraced by my Freakonomics friend and co-author, Steve Levitt.

Steven Levitt: Most of the time, I'm just lazy. You know, I could be investing in the kids or I can be, you know, indulging my own hobbies and sleeping and things. And so I'm sort of lazy. The other problem is that I have four kids. If you have too many kids, you can't invest that heavily into any one of them, because you go crazy.

Ryssdal: Amen, brother. I mean, if it's good enough for Steven Levitt, it's good enough for me, that's all I have to say.

Dubner: Hey, have a nice lazy Father's Day, Kai.

Ryssdal: I will do that, you too. Stephen Dubner, FreakonomicsRadio.com is his website. We'll see you in a couple of weeks.

Dubner: Thanks Kai.