When You Are Born Matters: The Impact of Date of Birth on Child Cognitive Outcomes in England. CEE DP 93
Author: Crawford, Claire
Date: 2007-10-00
Type: Numerical/Quantitative Data
Subjects: Foreign Countries,Child Development,Age Differences,Age Grade Placement,School Entrance Age,Cognitive Development,Educational Policy,Policy Analysis,Comparative Analysis,Outcomes of Education,Gender Differences,Student Characteristics,Socioeconomic Influences,Disadvantaged,Public Schools,Test Results,Academic Achievement,Cognitive Tests,School Districts,Admission (School),Admission Criteria,Cohort Analysis,Longitudinal Studies,Special Needs Students,Cognitive Ability,Academic Ability,Educational Testing

The impact of date of birth on cognitive test scores is well documented across many countries, with the youngest children in each academic year performing more poorly, on average, than the older members of their cohort (see, for example, Bedard and Dhuey (2006) or Puhani and Weber (2005)1). However, relatively little is known about the driving forces behind these differences, at least in England; nor does there appear to have been a robust discussion regarding what, if anything, should be done in light of these disparities. The authors address both of these issues in this report. In England, the academic year runs from 1 September to 31 August, so that a child born on 31 August will start school (and sit exams) up to a year earlier than a child born only one day later, on 1 September. Furthermore, as responsibility for determining school admissions policies falls on local, rather than central, authorities, there is considerable geographical variation in terms of length of schooling (and the age at which children start school) amongst the youngest members of each cohort. In this report, the authors use this framework to address four specific research questions: (1) What is the extent of the August birth penalty across different outcomes, and how does this vary by age (from age 5 to age 18)?; (2) The authors then move on to consider the impact of different school admissions policies on the outcomes of August-born (as well as January-, March- and May-born) children; (3) Observed differences between the outcomes of August- and September-born children could be due to a number of factors: (1) Age of sitting the test (absolute age) effect; (2) Age of starting school effect; (3) Length of schooling effect; and (4) Age position (relative age) effect. Which of these factors--absolute age, age of starting school, length of schooling, age position--drive differences in cognitive outcomes between August- and September-born children?; and (4) Does the August birth penalty vary across particular subgroups of interest? The authors use administrative data on all children in state schools in England to answer these questions. These data comprise test results from the Foundation Stage (sat at age 5), Key Stage 1 (age 7), Key Stage 2 (age 11), Key Stage 3 (age 14), Key Stage 4 (age 16) and Key Stage 5 (age 18), plus some basic background characteristics collected via an annual schools' census. The main results indicate that there is evidence of a significant August birth penalty in all outcomes and at every age for children in English state schools. Findings suggest that admissions policies do matter, at least for early cognitive outcomes. In general, August-born children are slightly better off (and certainly no worse off) if they start school in the September of the academic year in which they turn 5 (rather than in the January or the April, as happens in some local education authorities). Furthermore, this is likely to be of greater benefit to girls than to boys. The results suggest that the major reason why August-born children perform significantly worse than September-born children in the Key Stage tests is simply that they are almost a year younger when they sit them. Whilst August-born children do benefit from starting school earlier rather than later (for example, in the September, rather than the January or the April, of their reception year), this makes only a modest positive contribution to test scores and only at early Key Stages. Age position effects are generally not important. Clearly, other policy options are needed in order to eliminate the August birth penalty. Whilst there are some significant differences in terms of the magnitude of the August birth penalty for children who are and are not eligible for free school meals (discussed in Chapter 8), perhaps the most important finding is the lack of significant differences amongst the majority of subgroups considered. This suggests that, in most cases, August-born children, regardless of observable characteristics, face the same disadvantage (in terms of cognitive outcomes) relative to September-born children. This suggests that policy options do not need to be tailored to the needs of particular subgroups: in theory, all August-born children should benefit from the suggestions that the authors make. Additional tables and figure are appended. (Contains 6 figures, 46 tables and 118 footnotes.)