Do Different Types of Assets Have Differential Effects on Child Education?: Evidence from Tanzania.

To assess the conventional view that assets uniformly improve childhood development through wealth effects, this paper tests whether different types of assets have different effects on child education. The analysis indicates that household durables and housing quality have the expected positive effects, but agricultural assets have adverse effects on highest grade completed and no effects on exam performance. Extending the standard agricultural-household model by explicitly including child labor, the study uses three waves of panel data from Tanzania to estimate the effects of household assets on child education. The analysis corrects for the endogeneity of assets and uses a Hausman-Taylor instrumental variable panel data estimator to identify the effects of time-invariant observables and more efficiently control for time-invariant unobservables. The negative effect of agricultural assets is more pronounced among rural children and children from farming households, presumably due to the higher opportunity cost of their schooling.

Overweight and poor? On the relationship between income and the body mass index.

Contrary to conventional wisdom, NHANES data indicate that the poor have never had a statistically significant higher prevalence of overweight status at any time in the last 35 years. Despite this empirical evidence, the view that the poor are less healthy in terms of excess accumulation of fat persists. This paper provides evidence that conventional wisdom is reflecting important differences in the relationship between income and the body mass index. The first finding is based on distribution-sensitive measures of overweight which indicates that the severity of overweight has been higher for the poor than the nonpoor throughout the last 35 years. The second finding is from a newly introduced estimator, unconditional quantile regression (UQR), which provides a measure of the income-gradient in BMI at different points on the unconditional BMI distribution. The UQR estimator indicates that the strongest relationship between income and BMI is observed at the tails of the distribution. There is a statistically significant negative income gradient in BMI at the obesity threshold and some evidence of a positive gradient at the underweight threshold. Both of these UQR estimates imply that for those at the tails of the BMI distribution, increases in income are correlated with healthier BMI values.

Socio-economic, behavioural and environmental factors predicted body weights and household food insecurity scores in the Early Childhood Longitudinal Study-Kindergarten.

Recent increases in obesity prevalence among children in developed countries are of policy concern. While significant positive associations between households' food insecurity status and body weights have been reported for adults, it is known from the energy physiology literature that energy requirements depend on BMR, anthropometric measures and physical activity. It is therefore important to model the bi-directional relationships between body weights and households' food insecurity scores especially for children that have evolving nutrient and energy requirements. The present paper estimated dynamic random effects models for children's body weights and BMI, and households' food insecurity scores using longitudinal data on 7635 children in the USA enrolled in 1st, 3rd and 5th grades (1999-2003) of the Early Childhood Longitudinal Study-Kindergarten. The main findings were, first, physical exercise and numbers of siblings were significantly (P < 0.05) negatively associated with body weights, while households' food insecurity score was not a significant predictor. Moreover, children's body weights were significantly lower in households with higher parental education and incomes; time spent watching television and in non-parental care were positively associated with weights. Second, models for households' food insecurity scores showed that poverty and respondents' poor emotional and physical health significantly increased food insecurity. Moreover, households with children who were taller and heavier for their ages faced significantly higher food insecurity levels. Overall, the results showed that household food insecurity was unlikely to exacerbate child obesity in the USA and it is important that children receive balanced school meals and perform higher physical activity.

Continuous and robust measures of the overweight epidemic: 1971-2000.

This article considers alternate measures of the overweight epidemic that are more robust to measurement error, continuous in the body-mass index (BMI) at the overweight threshold, and sensitive to changes in the BMI distribution. The measures suggest that prevalence rates may understate the severity of the overweight problem. Since 1971, the prevalence of overweight has increased by 37%, while the distribution-sensitive measure has increased by 173%. Furthermore, although Hispanics have the highest prevalence of overweight, the distribution-sensitive measures reveal that overweight Hispanics exceed the overweight threshold by the smallest proportion (21%), whereas overweight non-Hispanic blacks exceed the threshold by 33%, on average.