Mutual insurance companies and stock insurance companies are different forms of organized risk sharing: policyholders and owners are two distinct groups in a stock insurer, while they are one and the same in a mutual. This distinction is relevant to raising capital, selling policies, and sharing...

We characterize how public insurance schemes are constrained by hidden financial transactions. When non-exclusive private insurance entails increasing unit transaction costs, public transfers are only partly offset by hidden private transactions, and can influence consumption allocation. We show...