Circumstances and efforts: how important is their correlation for the measurement of inequality of opportunity in health?

The way to treat the correlation between circumstances and effort is a central, yet largely neglected issue in the applied literature on inequality of opportunity. This paper adopts three alternative normative ways of treating this correlation championed by Roemer, Barry and Swift and assesses their empirical relevance using survey data. We combine regression analysis with the natural decomposition of the variance to compare the relative contributions of circumstances and efforts to overall health inequality according to the different normative principles. Our results suggest that, in practice, the normative principle on the way to treat the correlation between circumstances and effort makes little difference on the relative contributions of circumstances and efforts to explained health inequality.