Sunday, March 25, 2007

Does Day Care "Cause" Kids to Act Bad? A Case Study Highlighting the Importance of Heterogeneous Treatment Effects

People seem to believe that social scientists can estimate treatment effects. Is day care "bad" for children? This New York Times article seems to say that "yes, a little bit" based on a giant expensive study. It doesn't appear that there was any random assignment of childrent into different treatments so maybe we should think a little bit about the selection process of how parents choose a "treatment" for their precious children.

I recognize that this isn't the "econometrics blog" but sometimes I like to wander to other subfields of economics. At the University of Chicago, I trained in labor economics and spent a lot of time in classes taught by the giants of this field so humor me for a minute here.

What types of parents send their kids into Day Care?

A. There is no grandparent who lives near by
B. The mother works full time
C. The family's permanent income is not high enough to afford a nanny

While there certainly are many Hilary Clintons (i.e power moms who earn a high salary), people who fit
this profile may have lower permanent incomes than households where there is a hedge
fund dad and a mom who stays home with the kids. This alone could explain the
observed negative "day care" treatment effect.

One issue that I am confused about in this article below relates to "essential heterogeneity". Parents have private information about their 3 year old's talents and personality. If a mom recognizes that she has a gifted child, is she more or less likely to stay home and work with the kid? If gifted children are less likely to
be sent to pre-school (learning begets learning, skill begets skill) as their parents
want to invest more in them, then this would also tend to generate the finding
that "day care" is bad for kids when the truth is that selection is generating this
fact rather than treatment.

It could be the case that an ungifted kid may be more likely to keep a mom home
as she attempts to help this child to "catch up"? In this case the selection would
go in the opposite way and day care would appear to lead to "better" children later in life.



March 26, 2007
Poor Behavior Is Linked to Time in Day Care
By BENEDICT CAREY

A much-anticipated report from the largest and longest-running study of American child care has found that keeping a preschooler in a day care center for a year or more increased the likelihood that the child would become disruptive in class — and that the effect persisted through the sixth grade.

The effect was slight, and well within the normal range for healthy children, the researchers found. And as expected, parents’ guidance and their genes had by far the strongest influence on how children behaved.

But the finding held up regardless of the child’s sex or family income, and regardless of the quality of the day care center. With more than two million American preschoolers attending day care, the increased disruptiveness very likely contributes to the load on teachers who must manage large classrooms, the authors argue.

On the positive side, they also found that time spent in high-quality day care centers was correlated with higher vocabulary scores through elementary school.

The research, being reported today as part of the federally financed Study of Early Child Care and Youth Development, tracked more than 1,300 children in various arrangements, including staying home with a parent; being cared for by a nanny or a relative; or attending a large day care center. Once the subjects reached school, the study used teacher ratings of each child to assess behaviors like interrupting class, teasing and bullying.

The findings are certain to feed a long-running debate over day care, experts say.

“I have accused the study authors of doing everything they could to make this negative finding go away, but they couldn’t do it,” said Sharon Landesman Ramey, director of the Georgetown University Center on Health and Education. “They knew this would be disturbing news for parents, but at some point, if that’s what you’re finding, then you have to report it.”

The debate reached a high pitch in the late 1980s, during the so-called day care wars, when social scientists questioned whether it was better for mothers to work or stay home. Day care workers and their clients, mostly working parents, argued that it was the quality of the care that mattered, not the setting. But the new report affirms similar results from several smaller studies in the past decade suggesting that setting does matter.

“This study makes it clear that it is not just quality that matters,” said Jay Belsky, one of the study’s principal authors, who helped set off the debate in 1986 with a paper suggesting that nonparental child care could cause developmental problems. Dr. Belsky was then at Pennsylvania State University and has since moved to the University of London.

That the troublesome behaviors lasted through at least sixth grade, he said, should raise a broader question: “So what happens in classrooms, schools, playgrounds and communities when more and more children, at younger and younger ages, spend more and more time in centers, many that are indisputably of limited quality?”

Others experts were quick to question the results. The researchers could not randomly assign children to one kind of care or another; parents chose the kind of care that suited them. That meant there was no control group, so determining cause and effect was not possible. And some said that measures of day care quality left out important things.

The study did not take into account employee turnover, a reality in many day care centers that can have a negative effect on children, said Marci Young, deputy director of the Center for the Child Care Workforce, which represents day care workers. Most employees are “egregiously underpaid and have no benefits,” Ms. Young said, and when they leave for other work, “children experience this as a loss, and that does have an effect on them.”

The study, a $200 million project financed by the National Institute of Child Health and Human Development, recruited families in 10 cities from hospitals, after mothers gave birth. The researchers regularly contacted the mothers to find out where their children were being cared for, and visited those caregivers to see how attentive and how skilled they were with the youngsters.

In 2001, the authors reported that children who spent most of their day in care not provided by a parent were more likely to be disruptive in kindergarten. But this effect soon vanished for all but those children who spent a significant amount of time in day care centers.

Every year spent in such centers for at least 10 hours per week was associated with a 1 percent higher score on a standardized assessment of problem behaviors completed by teachers, said Dr. Margaret Burchinal, a co-author of the study and a psychologist at the University of North Carolina.

The Children’s Defense Fund estimates that 2.3 million American children under age 5 are in day care centers, many starting as toddlers and continuing until they enter kindergarten. Some 4.8 million are cared for by a relative or a nanny, and 3.3 million are at home with their parents.

The study was not designed to explain why time in day care could lead to more disruptive behavior later on. The authors and other experts argue that preschool peer groups probably influence children in different ways from one-on-one attention. In large groups of youngsters, disruption can be as contagious as silliness, studies have found, while children can be calmed by just the sight of their own mother.

“What the findings tell me is that we need to pay as much attention to children’s social and emotional development as we do to their cognitive, academic development, especially when they are together in groups,” said Ellen Galinsky, president of the Families and Work Institute, a nonprofit research group.

Loudell Robb, program director of the Rosemount Center in Washington, which cares for 147 children ages 5 and under at its main center and in homes, said she was not surprised that some children might have trouble making the transition from day care to school.

“At least our philosophy here is that children are given choices, to work alone or in a group, to move around,” Ms. Robb said. “By first or second grade, they’re expected to sit still for long periods, to form lines, not to talk to friends when they want to; their time is far more teacher-directed.”

And as parents in the thick of it know all too well, the stress of juggling chores, work and young children does not help. “It’s not an easy ride,” Ms. Robb said, “and you can see that here at drop-off time and in the evening when kids are picked up.”

The continuing research project began in 1991. The investigators have financing to follow the same children into high school, and are proposing to follow some into their 20s.

1 comment :

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