the households (for example, Filmer and Pritchett 2001; Rutstein and Johnson 2004). The descriptive statistics for the main variables used in this paper are shown in Table 1.

The NFHS data provide measurements of height and weight for children under 48 months of age in 1992/1993, under 36 months in 1998/1999 and under 60 months in 2005/2006. For comparability between the different NFHS rounds, we restrict our sample to children less than 36 months of age. We focus on the age-adjusted measures of heightfor-age (HAZ) and weight-for-age (WAZ), which reflect the children’s development relative to a reference population of well-nourished children<sup>4</sup> (WHO 2006). These measures reflect different dimensions of the children’s development: height-for-age (stunting) reflects the long-term effects of malnutrition, while weight-for-age (underweight) reflects both long- and short-term dietary effects (WHO 1995).

Malnutrition is highly prevalent in India. About 80 percent of children under the age of 3 were mildly, moderately, or severely underweight in 1992, with minimal changes in 1998 and 2005<sup>5</sup> . In 1992, 72 percent of boys and 70 percent of girls were stunted. The proportion of stunted children had decreased to 65 percent by 2005. According to NFHS data, the overall averages of HAZ and WAZ rose over the years for both boys and girls. Figure 1 demonstrates that the average HAZ had risen for boys from -1.9 in 1992 to -1.5 in 2005; WAZ grew from -2.0 in 1992 to -1.8 in 2005. Girls experienced similar improvements in health outcomes between 1992 and 2005.

The distribution of births by calendar months for the three rounds of NFHS is presented in Figure 2<sup>6</sup> . The proportions of boys and girls born in each month are similar. The highest birth rates are registered in August, September and October--these children

> **4** A report by Nutrition Foundation of India concluded that the WHO standard was generally applicable to Indian children (IIPS 2000, page 265). The nutritional status of children calculated according to these measures is compared with the nutritional status of a reference population recommended by the WHO (Dibley et al. 1987). The use of this reference group is based on the empirical findings that well-nourished children in all populations for which data exist follow similar growth patterns (Martorell and Habicht, 1986). Across the NFHS rounds, about 10 percent of eligible children were not measured, either because the children were not at home or because their mothers refused to allow the measurements (Lokshin Das Gupta and Ivaschenko, 2005).

> **5** A child is considered to be mildly underweight if its WAZ is from -1 to -2 standard deviations (SD) from the mean. Children with WAZ from -2 to -3 SD are considered to be moderately underweight, and children with WAZ less than -3 are considered severely underweight. Similar ranges are applied for stunting categories of HAZ.

> **6** The results shown in Figure 2 are calculated based on the sample of children younger than 36 months of age born in every household. This sample includes children who did not survive. The distribution of birth by month, constructed based on the sample of survived children, is similar to the one shown in Figure 2.

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