Why should insurance markets operate in this way? One simple and obvious explanation is moral hazard. Because the insured can often bring about, or at least make more likely, the event being insured against, insurance companies want to limit the amount of insurance their customers buy. Companies want to see that their customers do not purchase so much insurance that they have an interest in an ac- cident occurring. Thus, companies will want to monitor the purchases of their customers. Issuing contracts of the sort described above is the obvious way to do so.