Valentina Tobia, Paola Bonifacci, Gian Marco Marzocchi
Symbolic versus non-symbolic training for improving early numeracy in preschoolers at risk of developing difficulties in mathematics
Research in developmental disabilities
response dramatic rise childhood obesity centers disease control cdc organizations advocated increasing amount time elementary school children spend physical education pe classes however little known effect pe child weight paper measures effect instrumenting child pe time states mandated minimum number minutes pe using data early childhood longitudinal study kindergarten cohort eclsk 19982004 results iv models indicate pe lowers bmi zscore reduces probability obesity among 5th graders effect concentrated among boys find evidence gender difference partly attributable pe complement physical activity boys whereas substitutes girls represents first evidence causal effect pe youth obesity thus offers least support assumptions behind cdc recommendations find evidence increased pe time crowds time academic courses spillovers achievement test scores