From 1991 to 2003, the fraction of Medicaid recipients enrolled in HMOs and other forms of Medicaid managed care (MMC) increased from 11 percent to 58 percent. This increase was largely driven by state and local mandates that required most Medicaid recipients to enroll in an MMC plan....

Objective. To analyze the impact of hospital mergers on treatment intensity and health outcomes. Data. Hospital inpatient data from California for 1990 through 2006, encompassing forty mergers. Study Design. I used a geographic-based IV approach to determine the effect of a zip code’s exposure...

State governments contract with health maintenance organizations (HMOs) to coordinate medical care for nearly 20 million Medicaid recipients. Identifying the causal effect of HMO enrollment on government spending and health care quality is difficult if, as is often the case, recipients have the...

I exploit a plausibly exogenous change in hospital financial incentives to examine whether the behavior of private not-for-profit hospitals varies with the share of nearby hospitals organized as for-profit firms. My results show that not-for-profit hospitals in for-profit intensive areas are...

This paper examines the relationship between gun ownership and crime. Previous research has suffered from a lack of reliable data on gun ownership. I exploit a unique data set to reliably estimate annual gun ownership rates at both the state and the county level during the past two decades. My...

This paper examines the relationship between gun ownership and crime. Previous research has suffered from a lack of reliable data on gun ownership. I exploit a unique data set to reliably estimate annual rates of gun ownership at both the state and the county levels during the past two decades....

Under the Affordable Care Act, individual states have discretion in how they define coverage regions, within which insurers must charge the same premium to buyers of the same age, family structure, and smoking status. We exploit variation in these definitions to investigate whether the size of...