Inequality of opportunity in health: a decomposition-based approach

This paper presents a decomposition-based approach to measure inequality in health that captures Roemer’s distinction between circumstances and effort. Our approach builds on a decomposition of the Gini index with heterogeneous responses and is extended to decompose an inequality of opportunity Gini index inspired by the “fairness gap†principle. An original feature of our empirical analysis is the use of objectively measured biomarker as health outcomes and as proxies for relevant effort variables. Using data from the Health Survey for England from 2003 to 2012, we find that circumstances are the leading determinant of inequality in cholesterol, glycated haemoglobin, fibrinogen and mean arterial pressure. Moreover, we find a strong interaction between circumstances and effort leading to a smaller effect of effort on health for individuals in worse circumstances. Among the effort factors, we find that healthy diet and physical activity play the largest role in shaping objective health.