Risk-sharing in insurance is analyzed, with a view towards explaining the prevalence of deductibles. First we introduce, in a modern setting, the main concepts of the theory of risk-sharing in a group of agents. This theory we apply to the risk-sharing problem between an insurer and an insurance...

Under a comonotonicity assumption between aggregate dividends and the market portfolio, the CCAPM formula becomes more tractable and more easily testable. In this paper, we provide theoretical justifications for such an assumption.

Frictionless economy is the new concept emerged from late 90s1. Its core idea is to remove the time both suppliers and customers spend on the trial and error on the price. So the markets always perform on the equilibriums. So markets can work in the perfect efficiency. But due to the various...