Finally, even if the researcher can correctly determine theplan’s price, plan features (e.g., deductibles, copayments, providernetworks) can vary extensively and in ways the researcher cannotalways observe. Thus, an individual who chooses not to purchasehealth insurance at a relatively low price may appear to have lowdemand, whereas she may in fact be reacting to the low quality ofthe offered plan. Even some employer plans can initially excludecoverage for a pre-existing condition, so an individual who choosesnot to enroll could be viewed by the researcher as having limiteddemand when she in fact could have very high demand for a morecomprehensive insurance plan.