Inequality and health: implications for social work.

By the time this article appears, we will have elected a new president and a congress. They will have to deal with one of the most important problems facing the nation, namely, the rapid growth in relative poverty, or inequality. The figures on inequality are staggering. During the past 20 years, the income received by the top 5 percent of families increased by 64 percent, while that received by the bottom fifth fell by 5 percent (Collins, Hartman, & Sklar, 1999). In 1998 the top 1 percent of the population had a greater net worth than the bottom 90 percent (Wolff, 2000). These trends have profound implications. In recent years researchers from around the world have focused on the social determinants of health (Wilkinson & Marmot, 2000). It seems increasingly clear that the health of populations is influenced primarily by social factors (Tarlov, 1996). Perhaps the most important of these factors is the distribution of income (Tarlov, 1999). The issue is not poverty, in the sense of material deprivation, but inequality. As Wilkinson and Marmot (2000) note: People further down the social ladder usually run at least twice the risk of serious illness and premature death of those near the top. Between the top and bottom, health standards show a continuous social gradient, so even junior office staff tend to suffer much more disease and earlier death than more senior staff [italics added] The social gradient exacts "a heavy social cost in terms of diminished labor productivity, social exclusion, rising incidence of crime, and the erosion of civil society" (Kawachi, Kennedy, & Wilkinson, 1999a, p. xi). This suggests that the United States will face a wide range of physical and behavioral health problems. This column summarizes the literature on inequality and health and considers its implications for social work. THE DECLINE OF INFECTIOUS DISEASE For much of human history, infectious diseases, such as smallpox, influenza, and tuberculosis, were the major cause of mortality and morbidity (Tarlov, 1996). Around 1800 death rates from infectious disease began to fall and life expectancy increased. In the United States between 1900 and 1973, the overall rate of mortality fell by nearly 70 percent, largely because of the decline in infectious diseases (McKinlay & McKinlay, 1977). During the same period, life expectancy increased from 49 years to 71 years (Sagan, 1987). What explains this change? Historically, infectious diseases were rooted in material deprivation, and their decline was closely linked with economic growth and "higher standards of living" (Tarlov, 1996, p. 79; Wilkinson, 1994). Yet, something else also may have been at work. The decline in infectious disease was not the result of declining rates of infection but to increasing rates of survival among infected individuals (Sagan, 1987). The increase in survival rates, in turn, may have been linked with the transition from premodern to modern societies. People in premodern societies faced unrelenting poverty and lived in "continual dread of catastrophe" (Sagan, 1987, pp. 23-24). Stress of this kind can have a wide range of negative effects on the body, particularly the immune system. The constant stress of premodern times may have been "an unrecognized factor in explaining the decreased resistance of premodern populations to infection and death" (Sagan, p. 40). Conversely, economic growth, by alleviating material deprivation, may have stimulated an "increased sense of psychological well-being," increasing resistance to infection and reducing rates of mortality (Sagan, p. 126). INEQUALITY AND HEALTH As infectious diseases waned, chronic diseases, such as heart disease, cancer, and diabetes, increased; these diseases currently "account for 75 per cent of the deaths in the United States" (Tarlov, 1996, p. 79). Although economic growth played a central role in reducing infectious disease, it has had a more limited effect on chronic disease. …