But fee-for-service insurance raises the problem that neither providers of health care nor consumers of health care have an incentive to weigh the costs of health care against the health benefits that it produces. Healthcare providers find themselves in a situation in which they can prescribe tests or treatments with reduced concern about cost (especially because patients lack the knowledge to evaluate the benefits). Health consumers are affected by the classic problem of moral hazard—that is, the desire of those who are insured to consume more of the insured service than they would if they faced the full price. Enrollees’ choices today can also affect their future health and health needs, leading to dynamic moral hazard.