Trying to Measure the Value of Preschool Education

The notion that all four-year-olds should be able to participate in preschool class in preparation for entry into kindergarten is excellent. Unfortunately, this idea soon becomes subject to the standard cost-benefit analysis: what benefits accrue from the investment. In order to perform this analysis, one must have something to measure. And, of course, the easiest measures to obtain are the results from standardized tests. The author of an article in The Economist attempts to follow this path and is left rather perplexed.

The attempt is made to evaluate this data on the efficacy of preschool education produced by the OECD (Organization for Economic Cooperation and Development). Notice that the study explores the effect of greater than one year of preschool compared to no preschool. The data utilized are the reading proficiency results from an international test given to fifteen-year-olds in 2009.

A quick glance at this chart would suggest that in most countries preschool education has a rather large beneficial effect. A lingering glance would hopefully notice that the three countries in which little benefit is observed are the US, South Korea and Finland. The problem with interpreting this graph is that the students from Finland and South Korea are among the very best performers on this international test. Some explanation is therefore required. And what might these results mean for the US? Why is its experience so different from that of the majority of countries?

The danger in trying to draw conclusions from such a chart as this is that educational attainment is a function of many variables: preschool preparation, quality of teachers and curriculum, parental support, peer pressure from other students, and cultural importance attributed to education. If one is to plot years spent in preschool versus reading proficiency, one has to begin by assuming that all preschools are equal. This is followed by the assumption that either all the other variables are equal or that they are all unimportant for each student. Finally, one has to assume that all students in a country are equivalent in order that a meaningful average might be taken. The OECD people apparently tried to sort through some of these issues, but it is, ultimately, too difficult a task.

Consider the case of Finland. Finland does not even have the same concept of preschool as that dominant in the US. They relegate their children to a play and recreation curriculum , what we would call nursery school, until age six. Six-year-olds then enter a form of kindergarten in which they are encouraged to be inquisitive and taught how to "learn how to learn." Formal schooling begins at age seven. Reading instruction begins at age seven. This system works quite well for the Finns. Can one then conclude that preschool is unnecessary? No! What Finland’s system emphasizes is the importance of socialization in childhood development. It tries to insure that each child enters the school program with a similar rich experience base so that each has an equal opportunity. Finland also recognizes that not all children are equally mature at age five; waiting until age seven gives them a more equal chance to progress.

While Finland takes a relaxed approach and does not give standardized tests to their children until they approach high school age, South Korea seems to be very results oriented and is very demanding of its students in applying a "fiercely competitive exam culture." Perhaps, any differences in student performance at entry into the school system are overwhelmed by this highly competitive environment.

The peculiar results for the US may be nothing more than a matter of statistics. The OECD data relates to a test of fifteen-year-olds in 2009. These students would have had to be in preschool in 1998. State-supported preschools back then probably covered fewer than 10% of children. Those most likely to be in preschool at that time were those whose parents could afford a private school and the poor. The parents of the former group will take care of their children’s education, so it is not surprising that for them preschool might not make a great difference. One might expect a bigger effect for the poor who might be participating in the Head Start Program. One must remember that preschool is only one component of an education. If children from poor families receive benefits from Head Start, for those benefits to persist the children must then be provided an adequate learning environment in later years, a highly uncertain prospect in our country. Again, a great benefit from preschool may not be observed.

One must also recognize that most countries listed in the chart above are relatively small and culturally homogeneous. The US by contrast provides 50 different school systems in almost as many different social and cultural environments. These disparate systems produce disparate results. The best state systems produce students that test as well as those of any country in the world; the worst school systems test as poorly as the lowest ranked countries of the world. Conclusions based on averages over this ensemble are risky.

What do we learn from this discussion?

Preschool is important, but it must be part of a career of quality education provided in a supportive environment. The most important contribution of preschool might be, as Finland has recognized, to level the playing field so that all children can at least start out from the same point.