Commentary: Value Judgments in Health Inequality Measurement

Commentary V alue judgments lurk beneath the surface in any study of health inequalities; analysts ought to understand them, make them explicit, and present results transparently to poli-cymakers so that they, rather than analysts, decide which set of value judgments should be invoked. that is the key message of the paper " Lies, Damned Lies, and Health Inequality measurements " 1 Kjellsson et al. remind us that all studies of health inequalities are implicitly or explicitly based on either an absolute or relative notion of equality, and that studies involving bounded variables also involve an implicit or explicit value judgment about whether it is inequalities in attainment (e.g., health) that matter or inequalities in shortfalls (e.g., ill health). the authors emphasize that the value judgment between attainment and shortfall gets intertwined in practice with the value judgment of whether it is absolute or relative inequality that matters. epidemiologists have often reported results for both absolute and relative inequalities , and shown that the choice of perspective can make a difference. For example, in an early study of socioeconomic inequalities in health, Pamuk 2 found that absolute inequality in mortality across social classes in england and Wales (measured using the slope index of inequality) was smaller in 1949–1953 than in 1930–1932, but relative inequality (measured using the relative index of inequality) was higher in 1949–1953. although the tools were developed early on by economists to look at both types of health inequality, 3 most economists have until recently analyzed relative inequalities in health much as their colleagues analyzing income inequality have focused largely on relative income inequality. an early article by Clarke et al. 3 was an exception: it looked at absolute and relative inequalities, and explored the relationship between the two when the outcome variable could be expressed in terms of attainments or shortfalls (the so called mirror issue). this theme got picked up a few years later. an article of mine 4 explored the bounds the concentration index (the econo-mist's analogue of the relative index of inequality) when the outcome variable is binary. this article led to a series of papers and exchanges 5–12 that simultaneously addressed the bounds issue and the mirror issue. In this debate, the question of absolute versus relative inequality resurfaced—initially only implicitly. In this Commentary, I offer some thoughts on, and practical suggestions regarding, the two interrelated issues highlighted by Kjellsson et al. (absolute …