In Medicare Part D, low income individuals receive subsidies to enroll into insurance plans. This paper studies how premiums are distorted by the combined effects of this subsidy and the default assignment of low income enrollees into plans. Removing this distortion could reduce the cost of the...

This paper shows how in Medicare Part D insurers' gaming of the subsidy paid to low-income enrollees distorts premiums and raises the program cost. Using plan-level data from the first five years of the program, I find multiple instances of pricing strategy distortions for the largest insurers....

Objectives: Medicare Part D is the voluntary program that provides insurance for prescription drugs to 37 million US elderly. This form of public insurance is delivered exclusively through a choice-based private insurance market, where Medicare pays various types of subsidies. The objective of...

The efficiency of publicly-subsidized, privately-provisioned social insurance programs depends on the interaction between strategic insurers and the subsidy mechanism. We study this interaction in the context of Medicare's prescription drug coverage program. We find that the observed mechanism...

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...