NATIONAL BUREAU OF ECONOMIC RESEARCH

NBER Working Papers and Publications by Ariane Breitfelder

Working Papers and Chapters and Reporter Articles

 March 2008 The Transition to Post-industrial BMI Values Among US Children with John Komlos, Marco Sunder: w13898 In our opinion, the trend in the BMI values of US children has not been estimated accurately. We use five models to estimate the BMI trends of non-Hispanic US-born black and white children and adolescents ages 2-19 born 1941-2006 on the basis of all NHES and NHANES data sets. We also use some historical BMI values for comparison. The increase in BMIZ values during the period considered was on average 1.3sigma (95% CI: 1.16sigma; 1.44sigma) among black girls, 0.8sigma for black boys, 0.7sigma for white boys, and 0.6sigma for white girls. This translates into an increase in BMI values of some 5.6, 3.3, 2.4, and 1.5 units respectively. While the increase in BMI ... August 2007 The height of US-born non-Hispanic children and adolescents ages 2-19, born 1942-2002 in the NHANES Samples with John Komlos: w13324 We examine the height of non-Hispanic US-born children born 1942-2002 on the basis of all NHES and NHANES data sets available. We use the CDC 2000 reference values to convert height into Height-for-Age z-scores stratified by gender. We decompose deviations from the reference values into an age-effect and a secular trend effect and find that after an initial increase in the 1940s, heights experienced a downward cycle to reach their early 1950s peak again only c. two decades later. After the early 1970s heights increased almost continuously until the present. Girls born in 2002 are estimated to be 0.35[sigma] and boys are 0.39[sigma] above their 1971 values implying an increase of circa 2.5 cm between birth cohorts 1971 and 2002 as an average of all ages (Table 3). Age effects are also subst...

National Bureau of Economic Research, 1050 Massachusetts Ave., Cambridge, MA 02138; 617-868-3900; email: info@nber.org