Inherent problems with multiple insurance funds and optional insurance

The basic concept of insurance is population solidarity. There are inherent risks in a population but the population absorbs the cost of risks to an individual by spreading the impact of incurred costs amongst the insured population. However, if the population is split into insured and uninsured groups, or into selectively groups (as with private insurance with pre-insurance selection either by the insurance company or the insured) the concept of population solidarity breaks down. Insurance systems must then typically deal with two inherent challenges: adverse selection and ex-post moral hazard.

Some national systems with compulsory insurance utilize systems such as risk equalization and community rating to overcome these inherent problems. Proponents of single-payer health care in the United States aim to provide the population of the country with health care from a single fund and thus avoid problems and costs associated with adverse selection, moral hazard, and private profiteering from