Image taken from https://www.thebalance.com/health-care-inequality-facts-types-effect-solution-4174842

Image taken from https://www.thebalance.com/health-care-inequality-facts-types-effect-solution-4174842

Introduction

       Income inequality in United States is a growing concern, and has been steadily rising over the past five decades (Telford, 2019). The widening gap between the nation’s richest and poorest families drives differences in how these groups experience the social determinants of health, including the neighborhoods that they live in, employment opportunities, and access to healthcare. Given the importance of income in determining access to resources, it is worth examining income inequality in practice. Specifically, examining the relationship of income and health sheds light on some of the implications of income inequality and the resultant social and economic stratification in the U.S.

Supporting Research

       There is a significant body of research that examines the relationship between income and health. In a joint publication, the Urban Institute and the Center on Society and Health draw linkages between income/wealth and health/longevity (Woolf et al., 2015). Broadly, the article states that “the greater one’s income, the lower one’s likelihood of disease and premature death,” and goes on to explain how income and health are connected at every income level, from very poor to very rich. People with lower incomes have higher risk of disease and illness, including diabetes, chronic arthritis, stroke, dental health problems, and mental health issues, among others. Woolf et al. (2015) makes the point that this relationship stems from a complex web of interconnected social, economic, and environmental factors present throughout one’s lifetime.
       Stronks et al. (1997) adds to the discussion of the relationship between income and health by considering how occupation plays a role in determining health outcomes. Their findings indicate that there is interrelationship between income, health, and occupation, largely explained by the high concentration of long-term disabled individuals in occupations with low or no income. Not controlling for employment or ability status was a serious limitation of this study, however.
       In addition to the research expressly stating a relationship between income and health, there is also scholarship devoted to explaining how this is the case. Daly, Boyce, and Wood (2015) postulate that this relationship is based on how money influences a person’s social rank, stating that it is “social position, rather than material conditions,” that explain the impact of money on human health. That is, the biological effects of social subordination are such that individuals with less cash and capital are more likely to face pressures that lead to negative health outcomes and premature mortality. This article uniquely addresses the relationship between income and health from a psychological perspective.
       It is important to note that income inequality not, just absolute income, impacts health outcomes as well. Kawachi and Kennedy (1999) delineate the mechanisms by which income inequality exacerbates negative health outcomes for lower-income groups. In this framing, societies with higher levels of income equality have better health outcomes in general. This article underscores the importance of mitigating income inequality through means such as investment in public goods, supporting social cohesion, and building social capital across class lines. The authors suggest addressing broader economic forces to positively impact U.S. health outcomes in general.
       Marmot (2002) explores the relationship between health and income from an epidemiological perspective, identifying that income may be related to health through either the material conditions that income impacts, or through the opportunities and social circumstances affected by income that impact health. Marmot also draws connections between income inequality and poor health outcomes, advocating for redistributive policies that spread resources and wealth across income levels.


Methodology

    With the prior research in mind, it is relevant to explore the relationship between income and health outcomes as reported by the General Social Survey from 1972-2018. The GSS is a biennial survey conducted with an area probability design, randomly choosing households from suburban, urban, and rural areas around the United States. A strength of the GSS is that it is a cross-sectional survey, allowing for a broad look at the U.S. population as a whole. Limitations include the GSS being a relatively small sample size (n=roughly 3,000 with each survey iteration), and the fact that it does not allow for a longitudinal view of individuals, but rather samples a different subset of people each time the survey is conducted.     The research question driving this project is, “What is the relationship between family income and health outcomes.” The independent variable, Family Income in Constant Dollars (coded by GSS as “realinc”) tracks self-reported income levels from 1972-2018 adjusted for inflation. The dependent variable, Condition of Health (coded as “HEALTH”), asks individuals to report health outcomes on a scale of Poor, Fair, Good, Excellent reported as numbers 1-4 (NORC, 2018).

Results

Overview of the Data

       From 1972-2018, the GSS collected 42,886 valid responses that measure both Health Outcomes and Family Income in Constant Dollars. Health Outcomes were measured reported as a range of 1-4, with the most common response being “Good/3” and the mean being 2.99. Family income was reported with a range of $227-$162,607, with a mean average income of $31,1714.22 and a standard deviation of $29,471.36.

Relationship Between the Variables

       To examine the relationship between Family Income in Constant Dollars and Health Outcomes, I used a correlation. Though health outcomes are presented in a categorical manner in the GSS survey format, in general, they are continuous, making correlation a more relevant tool than a t-test.

       In this data, there is a correlation of .228 between Family Income in Constant Dollars and Health Outcomes, indicating a positive relationship between the two variables. As p<0.05, this relationship is statistically significant. As income increases, health outcomes also become slightly better, as visualized with the line of best fit in the graph below.

Discussion

       The findings above indicate a positive relationship between family income and health outcomes, based on the correlation of .228. This relationship is statistically significant, and fairly substantively significant as well, particularly when compared to other public health and social science issues that garner attention.
       It is worth noting, however, that a positive relationship between family income and health outcomes does not necessarily speak to causality. There are myriad factors that directly influence health that are beyond the scope of this paper, including many social determinants of health that are impacted by income. For example, a low income may not directly cause cancer, but may force a family to move to a neighborhood located next to a toxic waste facility which may ultimately cause cancer years later, or which may be farther away from work and allow for less time for physical activity, causing a decline in health, etc. As mentioned in the background research preceding the findings, lower incomes limit access to resources, opportunities, and social status that ultimately impact health outcomes, while income inequality compounds these issues. The findings presented in this paper echo the findings in the literature reviewed.
       These findings also suggest that social safety net policies intending to impact health outcomes must adopt a broad understanding of the relationship between poverty and health. Though income is undoubtedly important in determining health outcomes and influencing social determinants of health, policies that support equitable access to public goods like education and healthcare, in addition to welfare and workforce development policies that directly increase family income, are necessary to produce positive health outcomes. Research examining the impact of increased access to public goods and reduction in wealth disparities will help further the conversation on the nuanced relationship between income and health.



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