1 Department of Health Administration and Policy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA. Electronic address: [email protected].
2 Department of Economics, University of Oklahoma, Norman, Oklahoma, USA. Electronic address: [email protected].
3 Department of Health Administration and Policy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA. Electronic address: [email protected].
4 Department of Health Administration and Policy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA. Electronic address: [email protected].