Sibling data and the family background influence on child health.

This study, using sibling data for the first time in health economics, explores the effects of family background on child health. The method used estimates the proportion of variance due to family influences via a correlation coefficient for sibling data for two child health measures: approximately 22 per cent of the variance in days missed from usual activities and 43 per cent of the variance in visits to the medical facilities may be attributed to family influences on child health status. These estimates are compared with those obtained by multivariate regression analysis, the customary method employed in exploring child health determination. The comparison underscores the value of the sibling information utilized in the first method: the regression analysis explains only one seventh of the total family background effect revealed through the sibling data. The estimates further indicate that the residual, nonfamilial determinants are a major source of influence on child health.