Exploring the relationships between income inequality, socioeconomic status and health: a self-guided tour?

While the US enjoys a standard of living unmatched by many nations around the world, the successes of this strong economic standing are not enjoyed by all. Income and wealth are unevenly distributed; further, widespread health disparities have been documented across racial, ethnic, and socioeconomic status (SES) groups. These facts form the basis for two reports recently published by the National Policy Association’s Academy for Health Services Research and Health Policy. Income, Socioeconomic Status and Health: Exploring the Relationships, edited by James A. Auerbach and Barbara Kivimae Krimgold, is a collection of 12 papers presented at an April 2000 conference of a similar name (the book title refers to ‘income’ while the conference title gave topbilling to ‘income inequality‘). Improving Health: It Doesn’t Take A Revolution, a monograph authored by Auerbach, Krimgold and Bonnie Lefkowitz, summarizes the introduction and conclusion to the larger collection. Consequently, we limit our comments to the edited volume. This collection of essays has two purposes. The first, as expressed in the book’s foreword, is to ‘put the extent and severity of these disparities before America’s leaders’. This more narrow goal is largely met. However, the broader goal of this volume is to describe the links from income inequality to health inequality and to discuss the policy implications of these links. On the question of whether the volume meets this objective, we feel the answer is ‘no’. The volume is organized in three parts. The first set of five chapters includes contributions from several prominent researchers in the field of public health which detail studies on the relationships between measures of SES and health. Each author provides a broad overview of either the link between income and health, or the link between income inequality and health. These reviews are to be commended for their coherent and consistent (albeit one-sided) introduction to the public health perspective on this literature. The second third of the volume consists of five chapters reviewing options for policy makers interested in reducing health inequalities. These authors point to steps such as tax and transfer policies (which follow directly from the conclusions of research studies presented in Part I), as well as policies to address health inequalities by race, labour market and workplace policies, and steps to improve access to and quality of medical care. The last third of the volume features two contributed chapters and a conclusion that provide both summary and calls for future actions, and, to some degree, critical commentary. The volume does best from the standpoint of presenting a set of descriptive facts about health disparities and income disparities in the US, and documenting numerous research studies on the determinants of health status and the link between SES and health. Examples of this contribution include the chapter by David R Williams which provides a well-documented exposition of racial disparities in health, their possible causes, and some steps that could be taken to rectify them, and the contribution by Nancy E Adler, who outlines a number of possible explanations for the observed correlation between SES and health. The volume also provides a clear introduction to a relatively new measure of SES—income inequality—and provides citations to a vast number of studies on the link between income inequality and health and possible pathways responsible for this link (see chapters by Ichiro Kawachi, Bruce P Kennedy, and Richard G Wilkinson). A third strength of the volume is the inclusion of data and experience from other countries that are grappling with similar disparities in health, namely Canada and the UK. Katherine S Newman’s chapter on the UK’s Acheson Report is a particularly noteworthy example of the use of international experience to guide US research and policy recommendations. Thus, in terms of providing America’s leaders (and researchers) with a basic introduction to health and economic disparities and an international context in which to view them, the volume hits its mark. Yet, it falters when it comes to guiding policy makers and researchers through the maze of facts and findings found in the scientific literature. While it is true that the volume’s summary statistics and correlations help to provide policy makers with some relevant background, the book fails to provide policy makers with guidance about the extent of causal relationships. This being absent, it is difficult to assess the efficacy of various policy proposals. In terms of providing evidence even for or against the existence of causal relationships from income inequality or SES and health, the volume is not very persuasive. © International Epidemiological Association 2002 Printed in Great Britain