The effect of state laws on the supply of advanced practice nurses.

This paper considers how the decision to enter advanced practice nursing (e.g., the occupations of nurse practitioner, certified nurse-midwife, nurse anesthetist, and clinical nurse specialist) is affected by State laws on the scope of practice of APNs. We find that enrollments in APN programs are 30 percent higher in States where APNs have a high level of professional independence. Our work differs from previous studies by estimating a fixed effects model on cross-sectional and time series data, to avoid problems of endogeneity of State laws.