1. Division of Health Systems Management and Policy, University of Memphis, Memphis, Tennessee, USA.
2. Department of Health Management and Policy, University of Iowa, Iowa City, Iowa, USA.
3. Department of Economics, and University of Iowa, Iowa City, Iowa, USA.
4. Department of Preventive and Community Dentistry, University of Iowa, Iowa City, Iowa, USA.
5. Public Policy Center, University of Iowa, Iowa City, Iowa, USA.
6. National Bureau of Economic Research, Cambridge, Massachusetts, USA.