Using a rich sample created from the Longitudinal Survey of Australian Children, we investigate the extent to which the relationship between body size at birth and early childhood cognitive skills is mediated by physical development indicators. Consistent with existing evidence from other countries, we find a significant relationship between body…

The problems of hypothesis testing and interval estimation of the squared multiple correlation coefficient of a multivariate normal distribution are considered. It is shown that available one-sided tests are uniformly most powerful, and the one-sided confidence intervals are uniformly most accurate. An exact method of calculating sample size to…

Head Start is the largest publicly funded preschool program in the U.S., and one of its primary goals is to improve the school readiness of low-income children. As has been widely reported, the first randomized trial of Head Start in the program's history found some evidence that it is achieving this goal. Receiving one year of Head Start had…