Evolving measures of provider market power

Many researchers assess the impact of provider market structure and market power on outcomes such as price. These studies use a variety of measures of structure and power, ranging from ad hoc measures often based on census boundaries to structural measures derived from economic models of provider-payer bargaining. We explain the shortcomings of ad hoc measures, and, through a series of “horse races” show that one leading structural measure, the “willingness to pay,” is a consistently better predictor of prices.