Inequalities across the income distribution in a variable y can be decomposed into their causes, and changes in inequality in y can be decomposed into the effects of changes in the means and inequalities in the determinants of y, and changes in the effects of the determinants of y. Inequalities in height-for-age in Vietnam in 1993 and 1998 are largely accounted for by inequalities in consumption and in unobserved commune-level influences. Rising inequalities are largely accounted for by increases in average consumption and its protective effect, and rising inequality and general improvements at the commune level