What Do Longitudinal Data on Millions of Hospital Visits Tell Us about the Value of Public Health Insurance as a Safety Net for the Young and Privately Insured?

Young people with private health insurance sometimes transition to the public health insurance safety net after they get sick, but popular sources of cross-sectional data obscure how frequently these transitions occur. We use longitudinal data on almost all hospital visits in New York from 1995 to 2011. We show that young privately insured individuals with diagnoses that require more hospital visits in subsequent years are more likely to transition to public insurance. If we ignore the longitudinal transitions in our data, we obscure over 80% of the value of public health insurance to the young and privately insured.