Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)

Graduate Group

Health Care Management & Economics

First Advisor

Guy David

Second Advisor

Robert J. Town


I study the effects of integration among generalist and specialist physicians on referral and

treatment choices, inpatient admissions, and the cost of medical care. I first construct a

novel data set that links the structure of physician organizations to physician behavior for

two groups of individuals deemed most likely to benefit from generalist-specialist integra-

tion: individuals diagnosed with hypertension and diabetes mellitus. Due to differential

selection across integrated and non-integrated practices, ordinary least squares regression

is unlikely to identify the effects of interest. To surmount the identification problem, I

simulate random assignment of beneficiaries to physician organizations in an instrumental

variables framework. My estimates confirm that integration among generalist and special-

ists significantly affects referral decisions and treatment patterns. I fail to detect evidence

that this kind of integration improves medical outcomes or reduces medical care spend-

ing. These findings strongly suggest that policies increasing generalist-specialist integration

in piece-rate or fee-for-service environments are unlikely to achieve their goals. Finally,

I consider the theoretical literature that might rationalize generalist-specialist integration

patterns. I show that most potential explanations are inconsistent with my evidence, save

for David and Neuman (2011), suggesting that task adhesion should be a focal point for

future research.