Self-insurance and market insurance substitutability: An established tenet reconsidered

We study the interaction between self-insurance and market insurance when accident losses are multivalued. We show that self-insurance and market insurance may be complementary when self-insurance expenses do not affect much the probability distribution of large losses and the loading factor is high. This contrasts sharply with the conclusion of Ehrlich and Becker (1972) who establish the substitutability between self-insurance and market insurance when the cost of an accident is single-valued.