WEALTH is an index of household wealth which is expected to have direct effects on both insurance status and preventive care by affecting ability to pay. The wealth index is generated using principal component analysis (PCA) of a set of household assets and quality indicators,2 and maximum likelihood estimation of the polychoric correlations between latent variables of these household characteristics (Kolenikov and Angeles 2004). The scoring coefficients of the first principal component are used to weight the household asset and quality indicators in the wealth index.3 The wealth index is generated separately for each country and for the combined sample. By construction, the first principal component explains the maximum common variation in these household characteristics; 33–44% of the variation in this case.