|
AUTHORS: Elizabeth Dhuey and Stephen Lipscomb PAGES: 27 DATE: September 2008 ABSTRACT: This study presents evidence that the age of students relative to their school cohort predicts whether they are evaluated for or classified as disabled. Using three nationally representative surveys spanning 1988-2004 and grades K-10, we find that an additional month of relative age decreases the likelihood of receiving special education services by 2.1 to 5.1 percent. Relative age effects are strongest for learning disabilities and virtually nonexistent for physical disabilities. We measure precisely-estimated relative age effects for boys starting in kindergarten but not for girls until 5th grade. We also find strong effects among white students but no apparent differences by socioeconomic quartiles. We also examine how relative age affects the probability of classification among evaluated students. The results are consistent with the interpretation that disability assessments do not screen for the possibility that relatively young students are over-referred for evaluation. In fact, a higher percentage of relatively young boys are classified with a disability among those boys who are evaluated. PPIC working papers present work in progress and may not be quoted or cited without permission of the author. Comments or suggestions, however, are welcome. |