Increasing socioeconomic disparities in adolescent obesity.

Recent reports suggest that the rapid growth in youth obesity seen in the 1980s and 1990s has plateaued. We examine changes in obesity among US adolescents aged 12-17 y by socioeconomic background using data from two nationally representative health surveys, the 1988-2010 National Health and Nutrition Examination Surveys and the 2003-2011 National Survey of Children's Health. Although the overall obesity prevalence stabilized, this trend masks a growing socioeconomic gradient: The prevalence of obesity among high-socioeconomic status adolescents has decreased in recent years, whereas the prevalence of obesity among their low-socioeconomic status peers has continued to increase.

Have we put an end to social promotion? Changes in school progress among children aged 6 to 17 from 1972 to 2005.

We examine trends over time in the proportion of children below the modal grade for their age (BMG), a proxy for grade retention, and in the effects of its demographic and socioeconomic correlates. We estimate a logistic regression model with partial constraints predicting BMG using the annual October school enrollment supplements of the Current Population Survey This model identifies systematic variation in the effects of social background across age and time from 1972 to 2005. While the effects of socioeconomic background variables on progress through school have become increasingly powerful as children grow older that typical pattern has been attenuated across the past three decades by a steady secular decline in the influence of those variables across all ages.