Longer Term Effects of Head Start

Little is known about the long-term effects of participation in Head Start. This paper draws on unique non-experimental data from the Panel Study of Income Dynamics to provide new evidence on the effects of participation in Head Start on schooling attainment, earnings, and criminal behavior. Among whites, participation in Head Start is associated with a significantly increased probability of completing high school and attending college, and we find some evidence of elevated earnings in one's early twenties. African Americans who participated in Head Start are significantly less likely to have been charged or convicted of a crime. The evidence also suggests that there are positive spillovers from older children who attended Head Start to their younger siblings.

Heat or Eat? Cold Weather Shocks and Nutrition in Poor American Families

We examine the effects of cold weather periods on family budgets and on nutritional outcomes in poor American families. Expenditures on food and home fuels are tracked by linking the Consumer Expenditure Survey to temperature data. Using the Third National Health and Nutrition Examination Survey, we track calorie consumption, dietary quality, vitamin deficiencies, and anemia in summer and winter months. We find that both rich and poor families increase fuel expenditures in response to unusually cold weather (a 10 degree F drop below normal). At same time, poor families reduce food expenditures by roughly the same amount as the increase in fuel expenditures, while rich families increase food expenditures. Poor adults and children reduce caloric intake by roughly 200 calories during winter months, unlike richer adults and children. In sensitivity analyses, we find that decreases in food expenditure are most pronounced outside the South. We conclude that poor parents and their children outside the South spend and eat less food during cold weather temperature shocks. We surmise that existing social programs fail to buffer against these shocks.

NNLO predictions for dijet production in diffractive DIS

Cross sections for inclusive dijet production in diffractive deep-inelastic scattering are calculated for the first time in next-to-next-to-leading order (NNLO) accuracy. These cross sections are compared to several HERA measurements published by the H1 and ZEUS collaborations. We computed the total cross sections, 49 single-differential and five double-differential distributions for six HERA measurements. The NNLO corrections are found to be large and positive. The normalization of the resulting predictions typically exceeds the data, while the kinematical shape of the data is described better at NNLO than at next-to-leading order (NLO). Our results use the currently available NLO diffractive parton distributions, and the discrepancy in normalization highlights the need for a consistent determination of these distributions at NNLO accuracy

Second order QCD corrections to gluonic jet production at hadron colliders

We report on the calculation of the next-to-next-to-leading order (NNLO) QCD corrections to the production of two gluonic jets at hadron colliders. In previous work, we discussed gluonic dijet production in the gluon-gluon channel. Here, for the first time, we update our numerical results to include the leading colour contribution to the production of two gluonic jets via quark-antiquark scattering.Comment: 8 pages, 4 figures, Proceedings of "Loops and Legs in Quantum Field Theory", Weimar April 201

Race, Children's Cognitive Achievement and The Bell Curve

In The Bell Curve, Herrnstein and Murray demonstrate that a mother's score on the Armed Forces Qualification Test is a powerful predictor of her child's score on a cognitive achievement test. We replicate this finding. However, even after controlling for maternal scores, there are significant gaps in the scores of black and white children which suggests that maternal scores are not all that matter. In fact, both maternal education and income are important determinants of child test scores, conditional on maternal AFQT. We argue that racial gaps in test scores matter because even within families, children with higher scores are less likely to repeat grades. However, conditional on both child test scores and maternal AFQT, maternal education and income also affect a child's probability of grade repetition. We conclude that, even if one accepts test scores as valid measures of 'nature', both nature and nurture matter. Finally, we show that the effects on child test scores of maternal test scores, education, and income differ dramatically depending on the nature of the test, the age of the child, and race. The results suggest that understanding the relationships between different aspects of maternal achievement and child outcomes may help us unravel the complex process through which poverty is transmitted across generations.