Justice is good for our health in two ways. At the "point of delivery," justice requires universal access to a system of health care that meets our health needs fairly under resource constraints. "Upstream" from the health care system, justice demands fair distributions of liberty, opportunity, and basic resources. Achieving these fair distributions—correctly specified, we think, by John Rawls’s theory of justice—turns out to be a crucial determinant of public health, so that justice improves overall population health while reducing health inequalities. Our policies must keep both pursuits of justice in view. Justice in the delivery of health care and background justice in the society are both good for our health.

With that brief summary of our view, we turn to the comments by respondents on our empirical, philosophical, and policy claims.

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Empirics

The empirical section of our essay presented some basic ideas about the social determinants of health for a general reader; we did not offer, as Marmor rightly says, a comprehensive discussion, let alone historical review, for an expert audience. Our brevity, however, may have produced some misunderstandings that we would like now to address.

Several respondents suggest that much health inequality can be attributed to the difference between the very poor and everyone else, rather than to inequalities in the population as a whole. If their claim is right, then public policy ought to focus on getting the very poor above an acceptable threshold, but should worry less about inequalities in the rest of the population.

Health inequalities are not simply a matter of the poor versus everyone else.

We are doubtful about the underlying claim. Recall that one of the most intriguing findings we reported is the socioeconomic gradient in health status: though the poorest individuals are at the greatest risk of dying compared to the richest, the excess risk for mortality does not stop there. Even individuals with household incomes in the $50,000 to $70,000 range experience excess risk of death compared to the most affluent group. This difference in risk of death cannot be due to the former being unable to afford the basic necessities of life; some other processes are at work. Moreover, this finding holds across countries and within relatively middle-income groups. We mentioned, for example, the Whitehall Study of British civil servants. The participants in this study might all be classified as white-collar workers with steady employment and access to universal health care; they were certainly not in poverty. Yet even in this reasonably well-off cohort, the lowest occupation grades have four times the mortality risks of the top grade. Health inequalities are not simply a matter of the poor versus everyone else.

In a similar vein, Ted Marmor and Marcia Angell suggest that the relationship between income inequality and health in the United States might be attributable simply to differences in pockets of poverty across states, so that the states with more or larger pockets of poverty would also have worse average health outcomes. Several recent studies have addressed this possibility by including individual income and health outcomes along with state-level measures of income distribution. These studies show that even when we control for individual income, thereby accounting for between-state differences in the number of poor individuals, individuals living in states with high levels of income inequality have poorer health outcomes than those living in more egalitarian states, regardless of their own individual income.

Income inequality is not a "mysterious" cause of undesirable health outcomes. It works through identifiable causal pathways, including unequal access to opportunities.

To be sure, individuals with the lowest incomes are worst off in health terms as well. But even those with middle incomes have worse health outcomes than their counterparts in states with more equitable income distributions. These studies show that the observed relationship between income inequality and health is not simply a function of the underlying association between individual income itself and health. Of course, being well-off is good for your health. But living in a more equal society is also good for your health.

Moreover, and finally, income inequality is not a "mysterious" cause of undesirable health outcomes. It works through identifiable causal pathways, including unequal access to opportunities such as education, healthy employment, and health care; reduced social cohesion; distortions in political participation; and the stress effects of relative lack of control. These pathways are in and of themselves important contributors to health and well-being and should serve as relatively uncontroversial levers for policy intervention.

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Philosophy

Social justice is an important value, independently of its impact on health. Ezekiel Emanuel and other respondents emphasize this point, and we entirely agree. We don’t just want justice exclusively because it promotes population health or a fair distribution of health care.

Nevertheless, health is such a basic good that any plausible account of justice must say something about the distribution of health care in a society. Amartya Sen’s theory, as Marmot notes, goes directly to the issue. According to Sen, the point of justice is to promote our "positive freedom," our ability to be and do what we choose. Disease and disability strike at the heart of that ability: they directly diminish our capability to function well. And because they do, justice directly requires an appropriate distribution of the social determinants of health.

Serious impairments of health mean serious limits on opportunities. Because justice requires such a reasonable array, we must ensure a proper distribution of the social determinants of health.

On John Rawls’s theory of justice, things are more complicated. Justice, according to Rawls, requires a fair distribution of basic liberties, opportunities, and economic resources: health does not figure directly in the view. Still, two lines of argument connect Rawlsian ideas of justice to concerns about health care. The first argument rests on the empirical discovery, described in our article, that achieving a fair distribution of liberties, opportunity, and economic resources also causes a fair distribution of population health. As Anand and Peter suggest, there might have been no such relationship between the principles of justice and a fair distribution of public heath. The principles might not have addressed the key social determinants of health at all, or might have resulted in greater health inequality. The second argument involves an extension of Rawls’s theory that does make the reduction of health inequalities a direct requirement of justice. The idea is that we cannot ensure to people the reasonable array of opportunities that justice requires without protecting healthy functioning: serious impairments of health mean serious limits on opportunities. Because justice requires such a reasonable array, we must ensure a proper distribution of the social determinants of health, once we discover what they are.

Anand and Peter find a "tension" between these two arguments: while we argue here that Rawlsian principles indirectly and fortuitously assure an equitable distribution of health, the extension of Rawls’s view proposed by Daniels directly requires equitable distribution because it includes an assurance of normal functioning in the guarantee of equal opportunity. So it may seem "redundant" to appeal to other principles as a way of securing the equitable distribution of health. In particular, it may seem redundant to emphasize the importance of fair income distribution for public health. Opportunity does it all.

We find neither "tension" nor "redundancy," but a happy convergence of two lines of argument. We do not intend to propose two theories of justice bearing on health but only one, the extended theory that addresses health through its affects on opportunity. When we discover what the key social determinants of health are, we conclude—via the equal opportunity principle—that justice requires these determinants to be distributed in whatever ways produce equity in the distribution of health. At the same time, we observe that the other principles of justice support a similar conclusion. So the theory produces a convergence, not tension or redundancy. Had the facts about the social determinants been different—for example, had greater income equality been detrimental to public health—we might have had a much more troubling result, inasmuch as different principles of justice, with independent value, might then have worked at cross-purposes.

Rawls has a way to blunt the force of Sen’s criticism: he can register the difference that a disability makes precisely as a difference in opportunity.

A final point on philosophy: Unlike Marmot, we see a convergence of Sen’s and Rawls’s view, at least once the extension of Rawls’s theory to health is made. In his early work, Sen argued that Rawls’s emphasis on liberties, opportunity, and economic resources obscured the problems produced by disease and disability. Consider two people with exactly the same liberties, opportunities, and economic resources, but one of whom is disabled: these two would have very different levels of positive freedom—different "capabilities for functioning," as Sen puts it—but Rawls’s theory would, he said, obscure this difference. So Sen urged that our views about justice should focus directly on our real capabilities for doing things, and not simply on our liberties, opportunities, and economic resources.

Once it is understood, however, that assurances of normal functioning are included in the idea of a reasonable array of opportunities, Rawls has a way to blunt the force of Sen’s criticism: he can register the difference that a disability makes precisely as a difference in opportunity. From Sen’s side, his Development as Freedom focuses on the protections of liberties and opportunities in ways that make him address issues long of central concern to Rawls. Terminology aside, there is less difference than meets the eye.

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Policy

A final set of comments relates to the role of health care in reducing health inequalities. Marmor and Emanuel take issue with our emphasis on reducing social disparities, and suggest that the more urgent public policy problem is lack of access to health care in this country. There is, of course, no gainsaying that medical care contributes to the health of individuals and populations. And as Barbara Starfield notes, primary care is particularly effective and important. It should not be overlooked in discussions of how society should go about reducing health inequalities.

We disagree with Marmor’s false forced choice analogy—that we must choose between expanding coverage of health care and devoting our energies to changing the social distribution of other resources.

Nonetheless, we disagree with Marmor’s false forced choice analogy—that we must somehow choose between expanding coverage of health care and devoting our energies to changing the social distribution of other resources (income, education, and opportunities for healthy work). These are not competing objectives, but synergistic goals. Popular support for universal health care coverage arises (when it does) out of a shared egalitarian ethos that is itself a product of maintaining a relatively short distance between the top and bottom of the social hierarchy. Witness, for example, the birth of the National Health Service, which arose in Britain during an unusually cohesive, egalitarian environment that followed the Second World War. Conversely, societies that tolerate a high degree of inequality, such as the United States, also have enormous difficulty in forging a consensus about providing such communal benefits as health care. When the social distance between the "haves" and "have nots" is wide, there is correspondingly little motivation for those who are already covered by health insurance to care about the plight of the uninsured.

A broader social movement seeking a more egalitarian distribution of resources may well be a pre-condition for conducting a meaningful national debate about universal health care (and for addressing the issues of power that Woolhandler and Himmelstein raise). It is probably no accident that the failed reform efforts of the Clinton administration appealed to middle-class self-interest and to the self-interest of large employers worried about costs, with no appeal to the moral considerations about equality and fairness that lie at the heart of universal coverage. To concentrate our efforts on expanding health care coverage just because it seems more "doable" is therefore to confuse the prescription with the cause of the underlying illness.

Marmor’s excellent book Why Some People are Healthy and Others Not rendered a valuable service by reminding us that access to health care is not the major determinant of health inequalities. Again, the experience of the National Health Service in Britain has taught us that provision of universal health care does not by itself eliminate or reduce health disparities (in fact, they have widened). The Whitehall Studies similarly indicate that among individuals who have access to the same health care service, there can be three- to four-fold differences in the risk of premature mortality according to one’s access to other resources (the amount of control on the job, prestige, income and wealth, and so on). In other words, a society interested in reducing health inequalities is unlikely to achieve it by focusing on the provision of health care alone. Policies to improve population health must concern themselves as much with the sources of health (and correcting inequalities in their distribution), as with the instrumental means of curing illnesses (i.e., the provision of health care).

Health is too important to be left to the doctors alone.

We would agree with the view that adding poor health to the list of outcomes associated with income maldistribution is unlikely to spark a revolution, or to make Americans care more about trends in income distribution. The point we wish to reiterate is that good health (which most people do care about) depends to a large extent on factors that lie outside the health care sector, and that a society wishing to reduce health inequalities needs to engage willingly in intersectoral efforts—early childhood investment, narrowing the income gap, ensuring healthy workplaces, and other similar policies mentioned in our essay.

Health is too important to be left to the doctors alone.