Rates and states: reflections on the health of nations

John Lynch1 and George Davey Smith2

1 Department of Epidemiology, Center for Human Growth and Development, and Institute for Social Research, University of Michigan, 109 Observatory Street, Ann Arbor, MI 48109-2029, USA.
2 Department of Social Medicine, University of Bristol, Canynge Hall, Whiteladies Road, Bristol, BS8 2PR, UK.

The Health of Nations. Why Inequality is Harmful to Your Health. Kawachi I, Kennedy BP. New York: The New Press, 2002, pp. 232 (HB), $25.95. ISBN: 1 565 84582 X.

Writing a book titled The Health of Nations1 is surely a daunting and ambitious task considering it is only one consonant removed from the popular title of Adam Smith’s famous Wealth of Nations.2 Nevertheless, Harvard social epidemiologists Ichiro Kawachi and Bruce Kennedy revel in the challenge and have managed to integrate a vast amount of information in an attempt to help us better understand why social inequality in its various forms can be damaging to health, happiness, and the quality of human existence. This book is primarily about the goals of economic development and how we should evaluate its successes and failures. In this sense the authors are onto something fundamentally important. Kawachi and Kennedy question whether Americans are happier or healthier as a result of all their accumulation and consumption of goods and services. They answer no. More snappily, they suggest that ‘chasing the American Dream can be hazardous to your well-being‘ (ref. 1, p. 37), and that ‘striving after fame and fortune should come with a government health warning’ (ref. 1, p. 37

While the book focuses on the US, the authors are aware of the implications for other nations, and lament that, ‘Unfortunately, the American brand of turbocapitalism seems to be rapidly catching on in the rest of the world’ (ref. 1, p. 190). It will be up to readers to judge the extent to which the US malaise described in the book is relevant to other countries with different political, historical, and cultural traditions. Nevertheless, while everyone knows America is different, there is still enough in this book to be of interest to an international audience.

The book is broad in scope and the authors paint an expansive landscape of the ills that characterize contemporary America, discussing increases in income inequality, working hours, and the inexorable rise of ever more voracious consumer culture in chapters such as, ‘Economic Goals and the Permanent Problem of the Human Race’; ‘Prosperity and Happiness’; ‘Keeping up with the [Dow] Joneses’; and ‘The Social Costs of Consumption’. In their chapter, ‘Stepping on the Hedonic Treadmill’, Kawachi and Kennedy write powerfully about the effects of longer working hours and the need for dual incomes on the quality of family life. They write:

‘The "global care chain" is complete when a mother’s love for her children becomes commodified, and the resulting "emotional surplus value" is passed on from (a) an older daughter from a poor family in a poor country, who cares for her siblings while (b) her mother works as a nanny caring for the children of an immigrant nanny, who, in turn, (c) works as a substitute mother for the child of a family in a rich country.’ (ref. 1, p. 129)

They argue that the US is immersed in a culture of competitive consumption where the good life is no longer defined by a finite set of material conditions for decent living. Instead we are somehow driven to consume goods and services that are aimed at increasing our relative standing in the community. We have become obsessed with ‘positional competition’. Not only does this positional competition—for goods we really do not need—not deliver us health and happiness, it has negative externalities for the environment and the quality of urban and rural life. They entertainingly illustrate the issue of positional goods with the story of the French philosopher Denis Diderot, who recalled how, when he obtained a grand new scarlet dressing gown, became slowly dissatisfied with the other contingencies of his daily life, although they had previously seemed perfectly satisfactory.

Readers familiar with Kawachi and Kennedy’s work on social capital and income inequality will recognize the links they make between rising economic inequality and perceptions of relative disadvantage. In their view, such perceptions of relative social position help drive positional competition and have negative impacts on people’s sense of self worth, and the quality of their social relationships. But, while negative self-perceptions and deteriorating social capital are themes in this book, the most dominant message is that the greatest sources of inequality are structural in nature, and the authors endorse greater investments in improving housing, work environments, urban sprawl, pollution control, education, legal frameworks, and developing a more transparent and accountable politics.

The book is intended for popular as well as academic audiences as suggested in the personalized subtitle—‘Why Inequality is Harmful to Your Health’. It is in some ways similar in style to Robert Putnam’s Bowling Alone3—it is highly readable and full of interesting facts about contemporary US society, including how baseball teams with greater pay inequality between the players have worse team performances over the season. But in spite of its title, this book does not argue a detailed case for the importance of inequality for population health, per se. It is about describing general social consequences of adopting more rabid versions of market capitalism. In fact, health does not even get a mention until Chapter 3 on page41—fully one-fifth of the way through the book. One reason for this might be that the basic argument—that inequality decreases quality of life—does not require data on health. Indeed, quantity of life may well be a relatively trivial contributor to overall quality of life in rich countries at the beginning of the 21st century. From this perspective, links drawn between inequality and population health are perhaps one of the weaker strands of the general argument advanced in this book.


    Is population health collapsing?
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 Is population health collapsing?
 Expanding the explanatory...
 The influence of life...
 Strengthening the evidence base...
 The Roseto Effect—What are...
 Conclusion
 References
 
If readers were to take the arguments in The Health of Nations at face value, they might get the impression that population health was collapsing in the US and within other capitalist economies— or that it shortly will collapse. Of course, we know that in many ways humans have never been healthier—at least as measured by commonly used indicators like mortality rates. Life expectancy continues to climb—even in the US—suggesting that something else needs to be brought into focus to more fully understand how multi-dimensional social inequality affects levels of population health. Indeed, it might be a tough sell to market the idea that capitalism has been unsuccessful in (ultimately) delivering better population health. Some would argue the exact opposite—capitalism has been spectacularly successful in improving overall levels of population health, albeit unevenly, more slowly, and less equitably than was possible or desirable. For more on the inter-play between capitalism, the politics of liberal democracy and health, interested readers should look for Simon Szreter’s latest historical perspectives on population health.4

Figure 1Go shows declining US all-cause mortality rates for both men and women from 1968 to 1998. The Figure also shows the sharp rise in income inequality—its steepest increase since the Depression.5 Of course, the trouble is that 30-year trends in all-cause mortality and income inequality run in opposite directions. Figure 2Go shows declining all-cause mortality rates over the last 30 years, for both blacks and whites in the US, at the same time that trends in voter participation6,7—a marker of social capital3—were also declining. Also note that decreases in voter participation were steeper among whites than blacks. These Figures clearly demonstrate that overall mortality has continued to decline in the US, at the same time as markers of the sorts of social malaise, described by Kawachi and Kennedy in terms of inequality and social capital, have worsened. These are problematic observations for those who see a direct causal link between social capital and population health.8,9 The ‘inequality is bad for your health’ argument—which we endorse in general terms—has to be able to explain such seemingly discrepant findings. One answer is to better understand time-lags and long-term trends, but such discussions are fairly rare in the health inequalities literature,10 although useful contributions are beginning to appear.11,12



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Figure 1 Income inequality (Gini) and sex-specific, age-adjusted all-cause mortality, US, 1968–1988

 


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Figure 2 Race-specific voting participation in presidential elections and age-adjusted all-cause mortality, US, 1968–1998

 

    Expanding the explanatory framework for the determinants of population health
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 Is population health collapsing?
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 The Roseto Effect—What are...
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Perhaps we need another dimension to the explanatory framework that is sketched in The Health of Nations, if we are to better understand the two most dominant features of population health over the last century—the simultaneous existence of widening disparities and overall advances in population health. Consideration of the massive secular improvements in population health that have occurred rarely enter into current accounts of the determinants of disparities in health. The fact that rates of many important diseases are going down in virtually all social groups is not currently part of the health inequalities discourse, and hence not central to considerations of the social determinants of population health. For instance, Figure 3Go shows the virtually continuous decline in infant mortality in the US in all race/ethnic groups, but at the same time increases in relative inequality between blacks and whites, especially since the 1950s.



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Figure 3 Race-specific infant mortality, US, 1900–1998

 
Several questions arise. How should those of us interested in population health understand the co-existence of better overall health and larger relative disparities between social groups? Is it possible that the determinants of overall population health are different from the determinants of disparities in health? Do the factors that influence overall health initially tend to increase inequalities in health between social groups?13 Is it possible that the mere existence of large relative disparities in health is not incompatible with certain population health policies having overall benefits—is this the price of overall success?14

These issues await further investigation, but in the meantime, it is also relevant to raise one more thorny issue for those of us interested in the social determinants of population health. What do we actually mean by ‘population health’—especially in regard to the issues raised in The Health of Nations and their implications for the sorts of social conditions most conducive to better quantity and quality of life? How do we judge a population to be healthy? We normally use measures like all-cause mortality, life expectancy, or disability- or quality-adjusted life years. These are useful summary measures, but they also mask heterogeneity. In future investigations into the social determinants of population health, we think that the practice of examining overall indicators can be complemented by unpacking population health, because different types of health outcomes have different determinants.15

In developed nations, there have been large declines in many infectious diseases, stomach cancer, stroke, and heart disease, while non-Hodgkins lymphoma, diabetes, obesity, depression, and suicide among the young have increased. It is likely that some population health outcomes, such as suicide, homicide, and violence, are sensitive to current social conditions, while others, such as stomach cancer and haemorrhagic stroke may be sensitive to social conditions in the past.16 What sorts of population health outcomes are likely to be affected by the social conditions described by Kawachi and Kennedy and within what time-frames are they likely to be effected? It is perhaps easier to imagine how such conditions could influence rates of depression, violence, self-rated health, or through behavioural responses affect obesity and diabetes, and understanding the short and long-term effects on these sorts of outcomes is precisely why Kawachi and Kennedy’s book is important. But would we predict that these social conditions will cause a reversal in the large declines in rates of heart disease or stroke that have been seen since the 1960s? Will we see a return of stomach cancer to its levels in the 1950s when it was the single largest cause of cancer mortality in most industrial nations?

Shkolnikov, McKee, and Leon17 have convincingly shown how the tumultuous political, economic, and social conditions in post-Soviet Russia—surely, at least as powerful as the social turmoil in the US described in The Health of Nations—had profound effects on rates of accidents, violence, and heart disease. This was largely through binge consumption of alcohol bought on by job losses, desperation, and hopelessness. In stark contrast, there was no effect on trajectories of declining rates of rheumatic heart disease, stomach cancer, or increasing rates of breast cancer—each of these outcomes simply continued their historical trajectories unabated. To understand the determinants of population health, it seems we will need to understand the determinants of the historical trajectories of the specific outcomes that comprise total population health. That will mean including an outcome-specific life course approach that attempts to integrate knowledge of disease causation across individual and population levels, and how these play out in succeeding birth cohorts over time.


    The influence of life course processes at the individual and population levels
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We thoroughly endorse most of what is laid out in the Health of Nations. However, there are some epidemiologically less satisfactory elements of the book, and consideration of how factors acting across the life course influence health in particular ways18,19 may help resolve some of these. First, the authors dismiss or fail to refer to recent evidence that one important pillar of their work—the association between income inequality and health outcomes across and within nations—now seems far from robust.20–24 For instance, while income inequality predicts infant mortality in the cross-section, the association with older adult mortality is actually in the wrong direction.21 If influences across the six and more decades of life of these older adults determine some of their health outcomes, would we expect a strong cross-sectional association with a factor that can change relatively rapidly over time, such as income inequality? In the case of the strongest evidence for an influence of income inequality on mortality—the associations across the States of the US25,26—statistical adjustment for education levels removes the effect.27 This could reflect the fact that educational achievement is largely determined in childhood and early adulthood, and is thus an indicator of the product of social investments made many decades before people die.

Second, the authors treat the continuous gradient between social position and health as a mystery, the only solution to which is a consideration that psychosocial factors are the primary cause. Here they walk a familiar path in modern health inequalities research.28 For example, in regard to the Whitehall study, it has been argued that a ‘gradient in mortality among civil servants who are not poor argues for the importance of psychosocial factors linked to position in the hierarchy’ (ref. 29, p. 1127). The existence of a socioeconomic gradient in heart disease mortality amongst predominantly middle-class groups—such as Whitehall civil servants—has been widely cited as evidence that psychosocial factors, generated by internalization of position within social hierarchies, must be important, since there is a little or no material deprivation in adulthood amongst these groups. This lack of adult material deprivation, combined with the apparent inability of conventional risk factors to account for the gradient,30 has lead to a widespread impression that psychosocial factors, therefore, must play an important causal role.

Psychosocial factors may well be part of the picture, but we should carefully examine the evidence in favour of a psychosocial contribution and consider plausible alternative hypotheses. Firstly, recent evidence suggests that the apparently low explanatory power of conventional risk factors in regard to heart disease is based on little evidence and has been over-sold.31 Secondly, the socioeconomic gradient in cardiovascular disease (CVD) amongst middle-class adults could also be generated by the cumulative effects of deprivation in childhood and across the life course. Such cumulative effects over the life course could plausibly generate a finely graded association between adult socioeconomic indicators and CVD.32 Disadvantaged childhood social circumstances will have been almost entirely absent amongst the most consistently privileged social groups (e.g. top-grade civil servants in Whitehall), but will have been experienced by a proportion of other middle-class groups in less-favoured adulthood social locations, even though they are just below the very top levels in the social hierarchy. This hypothesis is supported by the Glasgow University student’s study, where childhood social circumstances strongly influenced CVD mortality—even amongst a relatively homogeneously affluent (in adulthood) population of those who were fortunate enough to attend university in the late 1940s in Scotland (Figure 4Go).33



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Figure 4 Age-adjusted sex-specific mortality from myocardial infarction in Roseto and Bangor, Pennsylvania, US, 1935–1984

 
The problematic nature of life course exposures and time lags between exposure and outcome received one aside in this book and are otherwise not covered. Indeed the authors give the impression that psychosocial influences on health running from perceptions of relative disadvantage to the health consequences of stress-mediated physiological changes in the body are near-instantaneous, when they write that if ‘the average [American] income suddenly doubled, the person earning $10 000 would be not only a lot poorer but also a lot less healthy’ (ref. 1, p. 64).


    Strengthening the evidence base for the importance of psychosocial factors in influencing population health
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 Is population health collapsing?
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As evidenced in other writings regarding psychosocial influences on health, the direct mechanisms linking psychosocial exposures to disease are poorly explicated and often discussed at an essentially metaphorical level. In this book, we never get beyond the idea that there are ‘physiological responses in individuals that damage their health in multiple ways’ (ref. 1, p. 51), which in this case is probably appropriate given its intended audience, and that such pathways are biologically very complicated.34 Nevertheless, the evidence cited in favour of psychosocial effects on health is perhaps weaker than is sometimes let on. For example, Kawachi and Kennedy discuss a much-cited small trial purporting to show that psychological counselling reduced recurrence risk and increased survival in breast cancer,35 but a comprehensive review of this issue shows that the balance of evidence is firmly on the side of no such benefit being evident.36,37 Similarly, we are told that the evidence on social support and health is as strong as it was on smoking and lung cancer when the US Surgeon General first declared on this issue in the 1960s (ref. 1, p. 127). But this is surely going too far, given the much smaller relative risks and the considerable potential for residual confounding and reverse causation on links between social support and health.

Over-generalizing the importance of psychosocial factors for health in the interests of popular consumption may not be the best long-term strategy. Kawachi and Kennedy’s Harvard colleague—social capital researcher Robert Putnam—probably lessened his credibility among public health professionals when he wrote that:

The bottom line from this multitude of studies: As a rough rule of thumb, if you belong to no groups but decide to join one, you cut your risk of dying over the next year in half. If you smoke and belong to no groups, it’s a toss up statistically whether you should stop smoking or start joining. These findings are in some ways heartening: it’s easier to join a group than to lose weight, exercise regularly, or quit smoking. (ref. 3, p. 331)

This is a naïve distortion of the epidemiological evidence and if readers take it to heart, potentially damaging to population health.38 And this is a pity, because Putnam, like Kawachi and Kennedy, is an impressive scholar who has important things to say. It is hard to imagine how putting the most positive interpretation on the evidence—even to the point of ignoring contrary findings—will ultimately help strengthen the case that psychosocial factors are indeed important determinants of some dimensions of population health.


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An illustration of these points is given by the treatment in this book of the famous ‘Roseto Effect’—related to the protection from heart disease apparently engendered by social solidarity in an Italian-American community in Pennsylvania.39 Kawachi and Kennedy admittedly mention this only briefly, but it has also been discussed by others,40 and is generally considered to be important evidence for psychosocial effects on health.

First, the Roseto Effect is built on a somewhat shaky epidemiological edifice. Figure 4Go is based on data presented by Egolf et al.,41 and shows the age-adjusted rates of death due to myocardial infarction (MI) in Roseto and its comparison community Bangor, from 1935 to 1984. The Roseto Effect is evident in the lower rates for men and women in comparison to Bangor between the mid 1930s and 1950s, and the subsequent increase in mortality from MI between 1955–1964 and 1965–1974, which was attributed to the coincident breakdown of social integration in Roseto.42,43 It is important to note that these effects are limited to MI. In the study that first reported on Roseto,42 there were no differences between these communities in rates of hypertensive or arterosclerotic heart disease death (without evidence of MI) —a sub-category of heart disease potentially related to pathological processes influencing MI. Subsequent studies also showed no differences in congestive heart failure.41 Figure 5Go is adapted from the data presented by Egolf et al.,41 and shows the age-specific male death rates for MI. The Figure shows that, in the earlier period from 1955 to 1964, there were identical MI rates in Roseto and Bangor for the youngest and oldest men aged 35–44 and >65. That means the age-adjusted Roseto Effect was driven by changes in MI mortality for men aged 45–54 and 55–64 years. While the rates in these age groups were low in Roseto from 1955 to 1964, they were based on only one and two deaths respectively. In 1965–1974 they were based on six and nine deaths respectively. The Roseto Effect for women was based on even smaller numbers. This does not mean the Roseto Effect was not ‘real’, but the very small numbers of deaths, combined with the lack of differences for other categories of heart disease, should perhaps warrant circumspect interpretation.



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Figure 5 Age-adjusted male mortality from myocardial infarction in Roseto and Bangor, Pennsylvania, US, 1955–1964 and 1965–1974

 
Secondly, an alternative explanation for the rise in MI among Rosetans in the 1960s could relate to life course processes. It is likely that conventional risk factor profiles of the Roseto inhabitants, whose families hailed overwhelmingly from southern Italy, were initially favourable compared with the predominantly ethnic German, English, Welsh, and Scots-Irish inhabitants of Bangor.43 In fact, such an interpretation is consistent with the results of several other studies conducted both before and after the Roseto investigations that have shown Italian immigrants and their first generation ancestors to have been relatively protected from CHD compared with immigrants and subsequent generations from northern European nations like Germany and Ireland.44–47 This protection from heart disease is, however, lost in the space of one to two generations—precisely the generations in which heart disease rates in Roseto began to rise to the levels experienced in Bangor.43 Bangor was populated by the ancestors of immigrant families from Northern Europe—a group with documented increased rates of heart disease compared with immigrants from southern Europe. While such intergenerational ethnic and/or genetic differences were considered by Roseto investigators,43,48 and earlier studies that showed Italian immigrants to be relatively protected from heart disease were mentioned49,50—the Roseto investigators nevertheless favoured an interpretation based on what was clearly their a priori idea, that loss of social solidarity and stress caused MI.48

Furthermore, even though standard risk factors such as blood cholesterol did not differ between Roseto and Bangor,51 we now know that such cross-sectional assessments are prone to error.31 Like the apparent ‘French Paradox’—of low heart disease rates despite high saturated fat intake and cholesterol levels—it turns out that it may not be so paradoxical after all, if saturated fat intake 30 years ago is assessed, at the time that the current elderly CHD patients began laying down their atheroma in earnest.52 Thus, we think intergenerational processes affecting the life course risk factor profiles of successive generations combined with long-term levels in the prevalence of known CHD risk factors in the population like smoking and high-fat diet from the 1920s to 1960s, are at least a plausible alternative explanation for what was observed in Roseto.

Finally, it is instructive to read how some of the original investigators interpreted their findings. According to Bruhn and Wolf:

The data obtained over a span of twenty years in the Italian-American community of Roseto, when compared with those of neighboring communities, strongly suggest that cultural characteristics—the qualities of social organization—affect in some way individual susceptibility to myocardial infarction and sudden death. The implication is that an emotionally supportive social environment is protective and that, by contrast, the absence of family and community support and the lack of a well-defined role in society are risk factors. (ref. 43, p. 134)

This is the usual message that has been extracted from the Roseto studies and used to support the positive role of psychosocial factors, like social capital, on health. But the author’s last phrase also hints at the potentially ambiguous nature of strong social ties. It reflects rather more conservative views in regard to the traditional roles of families, religion, and local social institutions as desirable—and health protective—forms of social capital. Elsewhere in the same book, Bruhn and Wolf state that by the early 1960s the signs of ‘community disintegration’ were already evident:

A few action seekers had begun to appear among Rosetans, mainly among the middle-class mobiles.... They entertained, travelled, and joined clubs outside the community in search of new experiences and opportunities.... Many of these middle-class mobiles and action seekers actually identified themselves as outsiders in Roseto. Nevertheless, they continued to live there although maladapted to the social order.... Our study found such individuals at high risk for the development of myocardial infarction ... (ref. 43, p. 122)

The cited evidence that they are at higher MI risk is two case studies describing details of their stressful, socially unconnected, and frustrating lives. Oh, and the authors also mention that one smoked two, and the other three, packs of cigarettes each day for 20 years before they died, but this was not interpreted as being as aetiologically important as the fact that they had apparently sought non-traditional club memberships and new experiences outside the traditional community. This Roseto story about the importance of traditional values, is certainly not the one promoted in the Health of Nations, but it echoes contemporary concerns about the potential for less-progressive deployments of the concept of social capital.38,53,54 Given what we have presented above, how much weight should we attribute to the ‘Roseto effect’ as strong evidence for the role of community ties in improving population health?


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Ichiro Kawachi and Bruce Kennedy are to be congratulated for writing this book because it engages readers in a dialogue over profound questions about the sorts of societies we want to live in, and importantly helps keep inequality on the population health agenda. Like Kawachi and Kennedy, we are advocates of the idea that the structural inequalities that cause the unequal social distribution of damaging exposures and protective resources are central to understanding patterns of population health. It is precisely these aspects of the social distribution of exposures that make understanding social capital and social networks important. But such investigations need to be linked to the social distribution of specific exposures and resources. Thus, we are less convinced that the general stress-mediated mechanisms they describe—related to relative social standing, positional competition, social support, and social capital—will causally affect all population health outcomes equally, if at all. We think the mechanisms that drive population health trajectories are likely to be much more specific to particular outcomes. This does not mean we disagree with their ‘big picture’ view that greater social equity is likely to be better for population health and quality of life.24 It seems the next step is to better understand how various dimensions of social equity are linked to the social distribution of specific risk exposures and resources, and thus affect particular population health outcomes and their trajectories over time. Evidence generated from such an historically and culturally contextualized individual and population life course approach may add to our knowledge of what drives the health of nations.


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Table 1 Relative risks for cause-specific mortality according to father’s social class among Glasgow University students
 

    Acknowledgments
 
John Lynch and George Davey Smith are supported by the Robert Wood Johnson Foundation, Investigator Awards in Health Policy Research. John Lynch is also supported by grants from the US National Institutes of Health (ROI HD35120-01A2; P50 MD38986-01). This work has also been facilitated by the European Science Foundation Program on Social Variations in Health Expectancy in Europe, of which John Lynch and George Davey Smith are members.


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1 Kawachi I, Kennedy, BP. The Health of Nations. Why Inequality is Harmful to Your Health. New York: The New Press, 2002.

2 Smith A. An Inquiry into the Nature and Causes of the Wealth of Nations. Edinburgh: 1776.

3 Putnam RD. Bowling Alone. New York: Simon and Schuster, 2000.

4 Szreter, S. The population health approach in historical perspective. Am J Public Health 2003;(forthcoming).

5 Lindert PH. When did inequality rise in Britain and America? J Income Distribution 2000;9:11–25.[CrossRef]

6 US Census Bureau. Reported Voting and Registration by Race, Hispanic Origin, Sex and Age Groups, November 1964–2000 [Web Page]. 2002; Available at (Accessed 16 December 2002).

7 US Census Bureau. Reported Voting and Registration by Region, Educational Attainment and Labor Force: November 1964 to 2000. [Web Page]. 2002; Available at (Accessed 16 December 2002).

8 Lynch JW, Due P, Muntaner C, Davey Smith G. Social capital: Is it a good investment strategy for public health? J Epidemiol Community Health 2000;54:404–08.[Free Full Text]

9 Muntaner C, Lynch JW, Davey Smith G. Social capital and the ‘Third Way’ in public health. Critical Public Health 2000;10:107–25.

10 Davey Smith G, Egger M. Commentary: understanding it all—health, meta-theories, and mortality trends. BMJ 1996;313:1584–85.[Free Full Text]

11 Blakely TA, Kennedy BP, Glass R, Kawachi I. What is the lag time between income inequality and health status? J Epidemiol Community Health 2000;54:318–19.[Free Full Text]

12 Lynch JW, Davey Smith G, Harper S, Hillemeier M, Ross N, Wolfson M. Is income inequality a determinant of population health? A focus on long-term cause-specific mortality trends in the United States. (unpublished manuscript.)

13 Victora CG, Vaughan JP, Barros FC, Silva AC, Tomasi E. Explaining trends in inequities: evidence from Brazilian child health studies. Lancet 2000;356:1093–98.[CrossRef][ISI][Medline]

14 Nybo Andersen A. Commentary: Social inequalities in risk of stillbirth —the price of success? Int J Epidemiol 2001;30:1301–02.[Free Full Text]

15 Davey Smith G, Gunnell D, Ben-Shlomo Y. Life-course approaches to socio-economic differentials in cause-specific adult mortality. In: Leon D, Walt G. Poverty, Inequality and Health. Oxford: Oxford University Press, 2000, pp. 88–124.

16 Leon DA, Davey Smith G. Infant mortality, stomach cancer, stroke, and coronary heart disease: ecological analysis. BMJ 2000;320:1705–06.[Free Full Text]

17 Shkolnikov V, McKee M, Leon DA. Changes in life expectancy in Russia in the mid-1990s. Lancet 2001;357:917–21.[CrossRef][ISI][Medline]

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23 Mackenbach J. Income inequality and population health. BMJ 2002;324:1–2.[Free Full Text]

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26 Kennedy BP, Kawachi I, Prothrow-Stith D. Income distribution and mortality: cross sectional ecological study of the Robin Hood index in the United States. BMJ 1996;312:1004–07.[Abstract/Free Full Text]

27 Muller A. Education, income inequality, and mortality: a multiple regression analysis. BMJ 2002;324:1–4.[Free Full Text]

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31 Beaglehole R, Magnus P. The search for new risk factors for coronary heart disease: occupational therapy for epidemiologists. Int J Epidemiol 2002;31:1117–22.[Abstract/Free Full Text]

32 Davey Smith G, Ben-Shlomo Y, Lynch JW. Lifecourse approaches to inequalities in coronary heart disease risk. In: Stansfeld S, Marmot M (eds). Stress and the Heart: Psychosocial Pathways to Coronary Heart Disease. London: British Medical Journal Books, 2002, pp. 20–49.

33 Davey Smith G, McCarron P, Okasha M, McEwen J. Social circumstances in childhood and cardiovascular disease mortality: prospective observational study of Glasgow University students. J Epidemiol Community Health 2001;55:340–41.[Free Full Text]

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