"And a chunk of those kids, several hundred of them, actually went to private school. And so this particular study was a way of looking at the associations between their enrollment in private schools and those outcomes at ninth grade."

"We had the opportunity to be studying about 1,300 kids that were born in 1991 at 10 different locations across the country, and we followed them — actually they're still being contacted at the age of 27 in this particular study — we followed them all the way through ninth grade in high school, and during the course of that study, we tracked the kinds of schools that they were in, we asked a lot of questions of the kids and the parents, and in the high school years, we assessed the children on a wide variety of things that we care about: achievement tests, how well they're doing in school, what the teachers think of them, how motivated they are.

Here & Now's Robin Young speaks with Robert Pianta , dean of the Curry School of Education at the University of Virginia and one of the study's authors.

The subtext, of course, is that expensive private schools give kids a better education, which leads to better career opportunities and a more successful life. But a new study shows that the advantages of private school disappear when controlling for socioeconomic factors.

"It was the family factors that carried the day in determining the children's performance in high school. It wasn't the school that they went to."

On the notion there are advantages to private schools, and that those advantages disappear when controlling for certain factors

"We look at these kids when we assess them in ninth grade, and if you just simply look at private school versus public school — don't consider any other factor in the kids' history — you see huge benefits to being in private school. They're about a standard deviation of like 15 points higher on test scores, they're more motivated and the like. And then as soon as you put into the equation that you're using to predict, as soon as you put in family income, those differences disappear — and they never reappear again, no matter how many other variables that you put in.

"So the idea basically being, that it's what's happening in kids' families and the kinds of conditions that they're able to purchase for their kids and the circumstances that they're able to provide for their kids over the long haul that really matter in adding up to the kinds of things that we assessed in ninth grade."

On the difference it makes when parents provided their young children with educational resources and stimulation

"That is a very big difference. Importantly, those families continue to give those kids advantages from kindergarten all the way through ninth grade. So it is important what happens in that birth-to-5 [years old] period for sure, it sets kids up on a trajectory of success or not. Those families that give those advantages tend to also be families that will place their kids in private schools.

"Now, some low-income kids do end up in private schools for all sorts of reasons. When we looked at the low-income kids in the sample who were in private schools, we didn't see any advantage to private education there either. I think one of the things people miss is the stunning heterogeneity of private education. We all have this idea of what private education looks like: It's like a prep school. But private education on average is very, very heterogeneous.

"If you want to predict children's outcomes — achievement test scores, the things we care about socially — in high school, the best thing that you can use to predict that is going to be family income. Regardless of what high school you go to, the best predictor is going to be family background. And in this case, it's family background before the child even goes to school in kindergarten. There will be individual cases of poor kids who went to private schools that are tremendous success stories. But we make policy not on the basis of individual cases, hopefully, we make it on the basis of larger data sets and patterns of information."

On Education Secretary Betsy DeVos calling the U.S. public school system a "dead end"

"I think we're saying that, for every school that she can point out where there's a public school that's a dead end, you can probably point out a private school that's also a dead end for a kid who needs a better education. So our point here would be a policy that essentially gave families vouchers, and allowed them to go use those vouchers for tuition in any private school. And remember, I talked about how heterogeneous these private schools are: In any private school, that kind of policy is not likely to add much value to kids' achievement long term for the large number of kids that need help in the United States, and particularly a policy like that without oversight, that would determine what type of school a child might go to — whether it was actually a decent one or not."

On whether this is a school issue, versus one that could be addressed by helping parents and kids at home

"Well we have lots of programs, social programs, that try to help improve parenting and provide stimulation to kids at home. And I think it's important to point out that the effects we see for schooling are small — they're not huge on average in the whole population, whether it's public or private school. There's lots of cases in which those effects are very, very positive for kids. And we have lots of evidence to suggest that when you improve schools — whether it's public schools or private schools or charter schools — you do improve the outcomes for kids, and so focusing on policies that improve schools are clearly the pathway to creating better achievement outcomes for kids, particularly kids from less advantaged households."

On advice for parents concerned about what kind of school their kids attend

"I think the parents who are struggling and really concerned about the schools that their kids are in, the best thing that they can do is get as involved as they possibly can be in the governance of that school and to use the mechanisms that are available to them to hold those public schools accountable. Many of those parents may have opportunities to look at publicly sponsored charter schools, and I think those are terrific opportunities. On balance, there aren't enough good schools for kids — whether those are public schools or private schools or charter schools. And we need parents to advocate for better schools."