The share of children attending early education programs in the United States has risen dramatically in recent years. Some 66 percent of four-year olds were enrolled in a pre-kindergarten center or a school-based preschool program in 2001. That's up from 23 percent thirty years earlier. Particularly striking, early education programs sponsored by school districts now serve one in seven four-year-olds. One frequent motivation for this early education is to insure that disadvantaged children with academic skill deficits are better prepared when they start school. But is it worth all the money and effort being spent in advancing children's school readiness?

Using a new rich source of data, researchers Katherine Magnuson, Christopher Ruhm, and Jane Waldfogel conclude in Does Prekindergarten Improve School Preparation and Performance?  that early education does increase reading and mathematics skills at school entry, but it also boosts children's classroom behavioral problems and reduces their self-control. Further, for most children the positive effects of pre-kindergarten on skills largely dissipate by the spring of first grade, although the negative behavioral effects continue. In the study, the authors take account of many factors affecting a child, including family background and neighborhood characteristics. These factors include race/ethnicity, age, health status at birth, height, weight, and gender, family income related to need, language spoken in the home, and so on.

Some details of their findings are significant. For example, disadvantaged children and those attending schools with "low levels of academic instruction" get the largest and most lasting academic gains from early education. On average, disadvantaged children (defined to include those from poor families or whose mother or father had not completed high school) scored in the 33rd percentile in reading, while those who attended pre-kindergarten had a score in the 44th percentile.

The behavior of disadvantaged children who attended pre-kindergarten was similar to that of the general population of children at school entry. But by spring of the first year, it got somewhat worse. They were in the 69th percentile in terms of problem behaviors. Attending pre-kindergarten, however, does not appear to increase the probability that a disadvantaged child will repeat kindergarten or be held back in first grade. Also, the behavioral effects may differ depending on whether or not the child continues on in kindergarten in the same school as the pre-kindergarten program.

From these findings, the authors conclude that for maximum effectiveness, further expansions of pre-kindergarten should be mainly focused on children who are disadvantaged or who will go on to attend low instruction schools. In 1990, governmental leaders endorsed as the first of eight national educational goals that: "By the year 2000, all children should enter school ready to learn." Nonetheless, the enrollment of disadvantaged children in early education programs remains relatively low - despite an increase in overall state spending on pre-kindergarten of 250 percent to $1.9 billion by the turn of the century.

Currently, the authors write, most state funding initiatives do target at-risk children, but funding falls far short of providing all eligible children with entry into these programs. Extra money to give these children an early education experience is likely to improve their early academic skills, they add.

In referring to the negative effects of early learning on behavior, the authors offer two important qualifications. First, classroom behavior is not necessarily indicative of behavior in other settings, say, being more aggressive at home. Second, the absolute levels of aggressive behavior found in this study were typically quite low, even for children who attended pre-kindergarten. Similarly, the levels of self-control were quite high, even for children who attended pre-kindergarten.

Nor does the federal Department of Education data used in the study -- a newly available, large, nationally representative sample of children who entered kindergarten in the fall of 1998 -- provide information on the long-term educational outcomes of children, for example whether low levels of problem behaviors do any damage to their level of achievement in later years. The behavior of the children was measured by how frequently a child fights, argues, gets angry, acts impulsively, or disturbs ongoing activities. Self-control was measured by how frequently the child respects the property of others, controls his or her temper, accepts peer ideas for group activities, and appropriately responds to peer pressure.

As a possible explanation for the behavioral effect, the authors note that pre-kindergarten programs usually have relatively high quality, as indicated by teacher education and pay, and probably are more academically oriented. This emphasis on basic skills, such as reading and math, may lead to a less positive social climate, with children receiving less individual attention and more punitive discipline.

David R. Francis

Abstract

Prekindergarten programs are expanding rapidly, but to date, evidence on their effects is quite limited. Using rich data from Early Childhood Longitudinal Study, we estimate the effects of prekindergarten on children's school readiness. We find that prekindergarten increases reading and mathematics skills at school entry, but also increases behavioral problems and reduces self-control. Furthermore, the effects of prekindergarten on skills largely dissipate by the spring of first grade, although the behavioral effects do not. Finally, effects differ depending on children's family background and subsequent schooling, with the largest and most lasting academic gains for disadvantaged children and those attending schools with low levels of academic instruction.