Ample evidence documents rising student obesity in summer months and falling student obesity during the school year. One theory for this pattern is that out-of-school days lack some of the structure and health-promoting behaviors that schools provide. Given this observed seasonal pattern, a natural question is whether there is room for policies…

In this meta-analysis, I have reviewed published and unpublished research on single-track, year-round education's effect on science and social studies achievement, 2001-2016. Of 30 studies that met inclusion criteria and had data from which an effect size estimate could be calculated, 7 reported science outcomes (18 effect size estimates) or…