nutritional status of children later in life (Schmidt et al. 2002). Indeed, recent studies have found a positive effect of access to health services on child nutritional status in Vietnam (Glewwe, Koch and Nguyen 2002) and in Colombia and Peru (Behrman and Skoufias 2004).

# **4. Analytical approach**

# **4.1 Data**

Data are drawn from a large-scale panel survey, the China Health and Nutritional Survey (CHNS). This paper utilizes four waves, from 1991 through 2000, and includes the seven provinces of Jiangsu, Shandong, Henan, Hubei, Hunan, Guangxi and Guizhou. The 1989 wave is excluded because in that year anthropometric data were not collected for children over the age of six years.

In each of the provinces, a multistage, random cluster procedure was used to draw the sample (see Henderson et al. 1994, for example, for an elaboration of the sample design). Counties in each province were stratified by income (low, middle, and high) and a weighted sampling scheme was used to randomly select 4 counties in each province. In addition, the provincial capital and a lower income city were selected where feasible. Villages and townships within the counties, and urban and suburban neighborhoods within the cities, were selected randomly.

In CHNS 1991, only individuals belonging to the original 1989 sample were re-interviewed; in CHNS 1993, all the new households that had been formed from the 1991 sample households who resided in sample areas were added; in CHNS 1997, all newly-formed households who resided in sample areas were once again added, plus additional households and communities to replace those no longer participating; and in CHNS 2000, newly-formed households, replacement households, and replacement communities were again added. In the seven provinces included in this analysis, there were 3,207 households in 1991, 2,986 households in 1993, 3,296 households in 1997 and 3,237 households in 2000 across 176 primary sampling units (or communities); there were 13,229 individuals in 1991, 12,492 individuals in 1993, 14,268 individuals in 1997 and 13,657 individuals in 2000.

# **4.2 Measurement of the variables**

The dimension of nutritional status with which this paper is concerned is linear growth – a measure of protein-energy malnutrition. Consequently, the dependant variable used is the height-for-age z-score (or the recumbent length-for-age z-score in the case of children under the age of 36 months). This measure is constructed on the basis of the 2000 Center for Disease Control (CDC) growth charts (Kuczmarski 2002). In line with the recommended exclusion ranges for implausible values, children with height-for-age z- scores that are less than -5 and greater than +3 have been excluded from the analysis (WHO 1995).

The measure of income used is the log of real per adult income. This measure is carefully constructed from the detailed income data in the CHNS to include multiple net cash income streams, the market value (as estimated by the household head) of in-kind income and the (estimated) market value of the quantity of home production consumed. Income is adjusted for temporal and spatial price variation using the China State Statistical Bureau’s (SSB) annual consumer price index ratio. Since fertility may be endogenous (Schultz 1976; Wolfe and Behrman 1992), real household income is deflated by the total number of adults rather than total household size.

An only-child is defined as someone under the age of 18 without siblings that are younger than 18.

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