Workers' compensation insurance presents a set of institutional charac teristics that are unique. For every other form of insurance, both the insurer and the coverage provided under the policy are completely controlled either by the federal or a state government, or by an arrangement between the insured and a property-casualty insurer. Unemployment insurance, Social Security, and bank-deposit insurance are examples for which a legis lative body sets the benefits. and a government agency prescribes the in surance premium. By contrast, the coverage and premiums for automobile, homeowners, and fire insurance are individual contractual arrangements between a policyholder and one of the more than 1800 U. S. property casualty insurance companies. Workers' compensation insurance, however, is a hybrid in which state legislatures stipulate the terms of coverage, while regulated competition is the major determinant of prices. State legislatures enact statutes that prescribe the replacement rate and duration of indemnity benefits, as well as full reimbursement of medical expenses. And although the manual rates for workers' compensation insurance continue to be administered by a prior approval process in most states, the competitive-market price for coverage is achieved through a variety of price-modification plans (Appel and Borba, 1988).