The Relationship between Auto Insurance Rate Regulation and Insured Loss Costs: An Empirical Analysis

This study points out a potential unintended effect of efforts to enhance affordability of insurance prices by regulating rates: It may ultimately lead to higher insurance costs. This is because rate regulation that suppresses insurance prices below competitive levels, or provides significant premium subsidies for some consumers, creates a variety of incentive distortions in the market. The article summarizes the theoretical arguments for this effect and provides empirical evidence of cost-increasing effects of rate regulation. The analysis uses state-level data on automobile insurance costs and claims rates for the period 1990 through 1998, and employs empirical methods that control for the possible reverse causation of high insurance costs leading to consumer demand for rate regulation. We find that bodily injury and property damage liability loss costs are higher in rate-regulated states, and that the bodily injury to property damage liability claims ratio is higher in regulated states