The spread of state any willing provider laws

Objective. To describe the growth of any willing provider (AWP) and freedom of choice (FOC) laws applicable to managed care firms and to explore empir ically the determinants of their enactment. Study Setting. A 1996 compendium of state laws and state-level data from th e 1991-1994 period. Study Design. Pooled cross-section time-series logistic regression of the d ecision to enact various types of AWP and FOC laws. Analysis uses a public choice framework to examine enactment. Key variables include proxy measures of proponent and opponent strength and the political environment. Principal Findings. The model works well for laws affecting hospitals, but performs poorly for physician and pharmacy laws. More providers are associa ted with the enactment of AWP and FOC laws. More large employers are associ ated with a reduced likelihood of enactment of some forms of the laws but n ot others. Conservative states are more likely to enact laws limiting selec tive contracting with hospitals and physicians. States with greater interpa rty competition are also more likely to adopt some types of legislation. Conclusions. The empirical results generally are consistent with the view t hat AWP and FOC laws are often enacted as a defensive strategy on the part of providers, but additional research is needed to provide a more definitiv e assessment of the determinants of these laws. Suggestions for future rese arch are provided.