Achieving Horizontal Equity: Must We Have a Single-Payer Health System? Michael K. Gusmano State University of New York, Downstate Medical Center Daniel Weisz International Longevity Center – USA Victor G. Rodwin New York University Abstract The question posed in this article is whether single-payer health care systems are more likely to provide equal treatment for equal need (horizontal equity) than are multipayer systems. To address this question, we compare access to primary and specialty health care services across selected neighborhoods, grouped by aver- age household income, in a single-payer system (the English NHS), a multiple-payer system with universal coverage (French National Health Insurance), and the U.S. multiple-payer system characterized by large gaps in health insurance coverage. We find that Paris residents, including those with low incomes, have better access to health care than their counterparts in Inner London and Manhattan. This finding casts doubt on the notion that the number of payers influences the capacity of a health care system to provide equitable access to its residents. The lesson is to worry less about the number of payers and more about the system’s ability to assure access to primary and specialty care services. Equity in Three Contrasting Health Systems The U.S. health care system presents a stark contrast to France and England, both of which provide universal health care coverage, albeit in different ways. France is an example of statutory national health insurance (NHI) systems that rely on significant mandatory payroll taxation, much like Social Security in the United States. It has multiple health insurance funds, but unlike the multipayer system in the United States, French health insurance funds all operate within a common framework in which no one is permitted to opt out of the system, health insurance funds are not Journal of Health Politics, Policy and Law, Vol. 34, No. 4, August 2009 DOI 10.1215/03616878-2009-018 © 2009 by Duke University Press