We use administrative data to measure whether attending a charter school in Denver, Colorado, reduces the likelihood that students are newly classified as having a disability in primary grades. We employ an observational approach that takes advantage of Denver's Common Enrollment System, which allows us to observe each school that the student…

Working memory capacities are associated with mathematical development. Many studies have tried to improve working memory abilities through training. Furthermore, the central executive has been shown to be the component of working memory, which is the most strongly related to numerical and arithmetical skills. Therefore, we developed a training…

Many states have implemented or expanded state-funded prekindergarten programs in the last decade, encouraged by claims about the benefits that can be expected and the importance of early experiences for children's development, especially for economically disadvantaged children. However, there is remarkably little methodologically adequate…

Recently, researchers have begun to employ rigorous statistical methods and developmentally-informed theories to evaluate outcomes for students retained in non-kindergarten early elementary school. However, the majority of this research focuses on academic outcomes. Gaps remain regarding retention's effects on psychosocial outcomes important to…

When a child does not seem to be ready for primary school, a popular practice is to grant the child more time by letting it repeat kindergarten. However, previous quasi-experimental research demonstrated negative, though diminishing, effects of kindergarten retention on academic learning during the first years of primary school. The present study…

As policymakers contemplate expanding preschool opportunities for low-income children, one possibility is to fund 2, rather than 1 year of Head Start for children at ages 3 and 4. Another option is to offer 1 year of Head Start followed by 1 year of pre-K. We ask which of these options is more effective. We use data from the Oklahoma pre-K study…

This study presents evidence pertinent to current debates about the lasting impacts of early childhood educational interventions and, specifically, Head Start. A group of students who were first studied to examine the immediate impacts of the Tulsa, Oklahoma, Community Action Project (CAP) Head Start program were followed-up in middle school,…

As policy-makers contemplate expanding preschool opportunities for low-income children, one possibility is to fund two, rather than one year of Head Start for children at ages 3 and 4. Another option is to offer one year of Head Start followed by one year of pre-k. We ask which of these options is more effective. We use data from the Oklahoma…

This study extends recent findings of a relationship between the relative age of students among their peers and their probability of disability classification. 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…

Given the recent rise in childhood obesity, the School Breakfast Program (SBP) and National School Lunch Program (NSLP) have received renewed attention. Using panel data on more than 13,500 primary school students, we assess the relationship between SBP and NSLP participation and (relatively) long-run measures of child weight. After documenting a…

This paper describes a classroom teaching experiment, concerning the concept of probability, with children aged 5 in a kindergarten school. The teaching experiment was based on constructivist and interactionist theories about the learning of school mathematics and lasted one month. The collection of the information was based on the tape-recorded…