The relationship between socioeconomic status (SES) and health is one of the most robust and well documented findings in social science. Anne Case et al. (2002) look at children in order to find the origins of the gradient, since the health of children may be assumed to have relatively little impact on their own socioeconomic status. They show that the well-known cross-sectional relationship between SES and health exists in childhood and is more pronounced among older than among younger children. This study confirms the results of Case et al. using a sample of Canadian children, despite the existence of universal health insurance coverage for doctor and hospital services in Canada. It finds that the gradient steepens in cross section, and that this result is robust to controls for cohort effects. However, little evidence is found that long-term effects of health shocks on future health are different for high-SES and low-SES children, even though in the short run, low-SES children suffer greater health losses than high-SES children after the arrival of a health shock. Instead, evidence is provided which suggests that the cross-sectional relationship between health, family income (or maternal education), and age arises primarily because low-income children are more likely to be subject to health shocks.