This study uses data from a comprehensive database of U.S. early childhood education program evaluations published between 1960 and 2007 to evaluate the relationship between class size, child-teacher ratio, and program effect sizes for cognitive, achievement, and socioemotional outcomes. Both class size and child-teacher ratio showed nonlinear…

For at least two decades, studies have demonstrated that the least experienced and credentialed teachers are concentrated in poor, minority, and low-performing schools. Some blame provisions in collective bargaining agreements (CBAs) between teachers unions and school districts that favor senior teachers. Seniority preference rules, they say,…