Does Changing Kindergarten Entry Cutoff Age Help Improve Educational Achievement?

Choosing when to enroll their children in kindergarten is a difficult decision for many parents. According to National Center for Education Statistics (NCES), more than nine percent of children just beginning kindergarten have already turned six years old, which is at least a year older than the required minimum entrance age for most US states. Many parents are concerned about their children’s cognitive and social ability in terms of their readiness to learn and interact with other children in kindergarten, as they do not want to see their children underperforming in relation to their peers.

Over the last 40 years, many states have moved their kindergarten entry cutoff date to earlier in the school year. More and more states have September or August cutoffs, while fewer states have cutoffs later than October, which used to be the norm. This trend has a direct effect on two fronts: It can increase the average age of students at school entry, as well as at the date of various state achievement tests further down the line. For example, a child turning five years old in November 2016 cannot be enrolled in a September-cutoff kindergarten in 2016. Instead, she needs to wait for next year’s enrollment, when she is almost six years old. This small difference may impact her educational achievement.

A recent study conducted by Jason Fletcher and Taehoon Kim explores the effects of state kindergarten entry age policies on children’s educational achievement and test score dispersion, which represents how spread out data are from an average state test score in fourth, eighth, and twelfth grades. To measure students’ educational achievement, the researchers used the National Assessment of Educational Progress (NAEP) scores in Reading and Math in fourth and eighth grades, as well as the ACT and SAT scores in Science, English, Math, and Reading in twelfth grade.

Earlier cutoffs generally mean that students are older when they begin school. This research shows a positive impact of an earlier kindergarten entry cutoff date among fourth and eighth graders, but the impact gradually fades for students by twelfth grade. The study suggests that the impact of an earlier kindergarten entry cutoff date is most significant among fourth graders. A one-month earlier kindergarten entry cutoff increases average reading test scores by 1.49 points and math scores by 1.35 points. The magnitude of this increase is relatively modest, yet important for many states—an increase in NAEP scores of only 1 to 1.5 points would increase their national ranking by several places. For example, Kentucky has an October 1 cutoff (as of 2008) and is ranked tenth. An increase of 1.5 points (by switching to a September 1 cutoff) is predicted to increase the state’s rank to between fifth and eighth.

As children advance to higher school grades, the positive impacts of early kindergarten entry cutoff tend to fade, though at different levels of magnitude for different subjects. The researchers find that the reading test scores bear the largest fade-out effect in eighth grade (an increase of only 0.47 points), compared to the impact on fourth grade reading test scores (an increase of 1.49 points). The fade-out effect is more obvious for twelfth graders’ ACT and SAT scores. The researchers find only very small and insignificant increases in those scores.

The fade out could be explained by many potential factors, such as the large time gap between kindergarten and twelfth grade, the stability of the data itself—as people may move across different states, and the decreased-age-at-test effect, which indicates a slowing and attenuating growth rate as people age (i.e., a one-year age difference is not as significant for a twelfth grader as it is for a child who is turning five years old).

In conclusion, from a state level, we can see why most states have an earlier kindergarten entry cutoff date compared to 40 years ago. An early cutoff date seems to improve the immediate educational performance of fourth and eighth graders. At the individual level, parents who find themselves struggling with whether or not to postpone their children’s kindergarten entrance should be cautious about their assumptions. A child’s development is a comprehensive journey—delaying kindergarten entry by one year may help a child perform a bit better in fourth grade, but as the fade-out effect here shows, the advantage obtained from being older than one’s peers dissipates. Parents should be cautious of these kinds of rules-of-thumb when deciding their children’s kindergarten entry year, carefully observing and evaluating the readiness of their children on a case-by-case basis.

Article Source: Fletcher, Jason, and Taehoon Kim. “The Effects of Changes in Kindergarten Entry Age Policies on Educational Achievement.” Economics of Education Review 50, 2016.

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