The COMPARE Microsimulation Model and the U.S. Affordable Care Act

Published In: International Journal of Microsimulation, v. 6, no. 3, Winter 2013, p. 78-117

Posted on on January 01, 2013

by Amado Cordova, Federico Girosi, Sarah A. Nowak, Christine Eibner, Kenneth Finegold

Read More

Access further information on this document at

This article was published outside of RAND. The full text of the article can be found at the link above.

In anticipation of upcoming health care legislation, the RAND Corporation developed a microsimulation model to forecast the responses of individuals, families and firms to such legislation. The COMPARE (COMPrehensive Assessment of Reform Efforts) microsimulation has been used to estimate the impact of major policy changes in the United States, such as the Affordable Care Act on uninsurance rates, participation in the group and the non-group insurance markets, firms' insurance offer rates, enrollment in public programs such as Medicaid and CHIP, private insurance premiums and costs to the federal and state governments. The team selected utility maximization to model behaviors, a methodology that is better suited than spreadsheet or econometric models to predict how individuals, households and firms will respond to wholly new insurance options, such as the Health Insurance Marketplace and the Small Business Health Options Program (SHOP) Exchanges created by the Affordable Care Act. Modeling can be done both at the national and at a state-specific levels. In this paper we provide a summary of COMPARE's basic principles, its nationally representative databases, its utility-maximization behavioral models, and how we have used COMPARE to estimate the consequences of the Affordable Care Act.

This report is part of the RAND Corporation External publication series. Many RAND studies are published in peer-reviewed scholarly journals, as chapters in commercial books, or as documents published by other organizations.

Our mission to help improve policy and decisionmaking through research and analysis is enabled through our core values of quality and objectivity and our unwavering commitment to the highest level of integrity and ethical behavior. To help ensure our research and analysis are rigorous, objective, and nonpartisan, we subject our research publications to a robust and exacting quality-assurance process; avoid both the appearance and reality of financial and other conflicts of interest through staff training, project screening, and a policy of mandatory disclosure; and pursue transparency in our research engagements through our commitment to the open publication of our research findings and recommendations, disclosure of the source of funding of published research, and policies to ensure intellectual independence. For more information, visit

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.