Accountable Care Organizations (ACOs) are new organizations created by the Affordable Care Act to encourage more efficient, integrated care delivery. To promote efficiency, ACOs sign contracts under which they keep a fraction of the savings from keeping costs below target provided they also...

We propose a "common-agency" model for explaining inefficient contracting in the U.S. healthcare system. In our setting, common-agency problems arise when multiple payers seek to motivate a shared provider to invest in improved care coordination. Our approach differs from other common-agency...