An Experimental Study of the Full-Coverage Puzzle

Abstract

One of the most intriguing questions in insurance is the preference of consumers to buy low or no deductible insurance policies. This stands in sharp contrast to the theorem, proved by Mossin, 1968, that when the price of insurance is higher than its actuarial value, then under quite reasonable assumptions full coverage is not optimal. We show in a set of experiments that amateur subjects tend to underestimate the value of a policy with a deductible and that the degree of underestimation depends on the level of the deductible. This implies that a policy with a deductible priced according to the true expected payments may seem "overpriced" to the insured and therefore may not be purchased. Since the values of full coverage policies are not underestimated, the insured may find them as relatively better "deals".