Open enrollment periods are pervasively used in insurance markets to limit adverse selection risks resulting when enrollees can switch plans at will. We exploit a change in the open enrollment rules of Medicare Advatage to analyze how beneficiaries responded to the option of switching to a...

Open enrollment periods are pervasively used in insurance markets to limit adverse selection risks resulting when enrollees can switch plans at will. We exploit a change in the open enrollment rules of Medicare Part C and Part D to analyze how Medicare beneficiaries responded to the option of...

Evidence on insurers' behavior in environments with both risk selection and market power is largely missing. We fill this gap by providing one of the first empirical accounts of how insurers adjust plan features when faced with potential changes in selection. Our strategy exploits a 2012 reform...

Evidence on insurers' behavior in environments with both risk selection and market power is largely missing. We fill this gap by providing one of the first empirical accounts of how insurers adjust plan features when faced with potential changes in selection. Our strategy exploits a 2012 reform...