@article {Ghossoub2017, title = {Arrow\&$\#$39;s Theorem of the Deducible with Heterogeneous Beliefs}, journal = {North American Actuarial Journal}, volume = {21}, number = {1}, year = {2017}, pages = {15-35}, abstract = {

In Arrow{\textquoteright}s classical problem of demand for insurance indemnity schedules, it is well-known that the optimal insurance indemnification for an insurance buyer{\textemdash}or decision maker (DM){\textemdash}is a\ deductible\ contract when the insurer is a risk-neutral Expected-Utility (EU) maximizer and when the DM is a risk-averse EU maximizer. In Arrow{\textquoteright}s framework, however, both parties share the same probabilistic beliefs about the realizations of the underlying insurable loss. This article reexamines Arrow{\textquoteright}s problem in a setting where the DM and the insurer have different subjective beliefs. Under a requirement of compatibility between the insurer{\textquoteright}s and the DM{\textquoteright}s subjective beliefs, we show the existence and monotonicity of optimal indemnity schedules for the DM. The belief compatibility condition is shown to be a weakening of the assumption of a monotone likelihood ratio. In the latter case, we show that the optimal indemnity schedule is a variable deductible schedule, with a state-contingent deductible that depends on the state of the world only through the likelihood ratio. Arrow{\textquoteright}s classical result is then obtained as a special case.

}, url = {http://www.tandfonline.com/doi/full/10.1080/10920277.2016.1192477}, author = {M Ghossoub} }