TY - JOUR AB - Title I and IDEA are complementary federal responses to different sources of low achievement. Title I targets opportunity-mediated underachievement, while IDEA targets persistent underachievement for which deficits in ordinary educational opportunity are not the primary explanation. A simple framework and stylized simulation show that performance-based IDEA increasingly converges toward the same opportunity margin already served by Title I. AU - Shores, Kenneth A. AU - Souto-Maior, Joao M. PY - 2026 ST - Title I and IDEA as Complementary Federal Responses: Distinguishing Opportunity-Mediated and Opportunity-Independent Underachievement TI - Title I and IDEA as Complementary Federal Responses: Distinguishing Opportunity-Mediated and Opportunity-Independent Underachievement UR - http://www.edworkingpapers.com/ai26-1443 ER -