Measuring Socioeconomic Status
4. Why SES Matters
This last point merits a little more attention. Figure 1 is a sketch of what I call the fundamental graph of public health. The figure is intentionally drawn in a cartoon-like fashion because it is not precise. In actuality, the slope and the intercept of the (regression) line varies by disease, time and place, and there are surely non-linearities to consider. Yet the core principle remains: the higher one’s SES, the greater their expected health. What is more, to the extent it reflects empirical reality, Figure 1 suggests that health may be improved in just two ways. First, a person or group’s health may be improved by moving them along the line, left to right, on the horizontal SES axis. Given the slope, this would increase the expected value of health (vertical axis) for the person or group. Political and economic efforts to enhance education or increase earnings are interventions consistent with this approach. Social scientists tend to focus on this class of potential interventions. Some economists often propose policies to increase a person’s educational opportunities (i.e., human capital) so that they may get a better job and increase their SES. Other economists may aim to increase a nation’s gross domestic product (GDP) in order to raise the entire slope (effectively changing the intercept) and improving everyone’s health. On the other hand, health may be improved while keeping SES constant. This is symbolized by the red-colored vertical line and associated question mark. Policies and interventions of this type tend to be medical in nature. Examples include vaccines, pharmaceuticals, and surgeries. Each of these interventions increases health without altering the fundamental social structure of society or a person or group’s SES. It follows, that the medical interventions are often easier to “sell” to the public since there is little dispute over the potential for restructuring society’s winners and losers. Interestingly, perhaps the greatest public health intervention ever stumbled upon, fluoridation of water, may be viewed as a combination of both approaches because it led to more productive workers and increased (oral) health directly.