[1] Univ New Mexico, Robert Wood Johnson Fdn Ctr Hlth Policy, Albuquerque, NM 87131 USA
[2] Univ New Mexico, Dept Econ, Albuquerque, NM 87131 USA
[3] RAND, Santa Monica, CA 90401 USA
[4] Univ So Calif, Sch Pharm, Schaeffer Ctr Hlth Policy & Econ, Los Angeles, CA 90089 USA
[5] Univ So Calif, Sch Pharm, Dept Pharmaceut Econ & Policy, Los Angeles, CA 90089 USA