The Impact of Organizational Boundaries on Healthcare Coordination and Utilization.

We measure organizational concentration-the distribution of a patient's healthcare across organizations-to examine how firm boundaries affect healthcare efficiency. First, when patients move to regions where outpatient visits are typically concentrated within a small set of firms, their healthcare utilization falls. Second, for patients whose PCPs exit the market, switching to a PCP with 1 standard deviation higher organizational concentration reduces utilization by 21%. This finding is robust to controlling for the spread of healthcare across providers. Increases in organizational concentration predict improvements in diabetes care and are not associated with greater use of emergency department or inpatient care.

Team Relationships and Performance: Evidence from Healthcare Referral Networks.

We examine the teams that emerge when a primary care physician (PCP) refers patients to specialists. When PCPs concentrate their specialist referrals-for instance, by sending their cardiology patients to fewer distinct cardiologists-repeat interactions between PCPs and specialists are encouraged. Repeated interactions provide more opportunities and incentives to develop productive team relationships. Using data from the Massachusetts All Payer Claims Database, we construct a new measure of PCP team referral concentration and document that it varies widely across PCPs, even among PCPs in the same organization. Chronically ill patients treated by PCPs with a one standard deviation higher team referral concentration have 4% lower health care utilization on average, with no discernible reduction in quality. We corroborate this finding using a national sample of Medicare claims and show that it holds under various identification strategies that account for observed and unobserved patient and physician characteristics. The results suggest that repeated PCP-specialist interactions improve team performance.

How important is price variation between health insurers?

Prices negotiated between payers and providers affect a health insurance contract's value via enrollees' cost-sharing and self-insured employers' costs. However, price variation across payers is difficult to observe. We measure negotiated prices for hospital-payer pairs in Massachusetts and characterize price variation. Between-payer price variation is similar in magnitude to between-hospital price variation. Administrative-services-only contracts, in which insurers do not bear risk, have higher prices. We model negotiation incentives and show that contractual form and demand responsiveness to negotiated prices are important determinants of negotiated prices.

Measuring Time Preferences.

We review research that measures time preferences-i.e., preferences over intertemporal tradeoffs. We distinguish between studies using financial flows, which we call "money earlier or later" (MEL) decisions and studies that use time-dated consumption/effort. Under different structural models, we show how to translate what MEL experiments directly measure (required rates of return for financial flows) into a discount function over utils. We summarize empirical regularities found in MEL studies and the predictive power of those studies. We explain why MEL choices are driven in part by some factors that are distinct from underlying time preferences.