General medical care in the United States has historically been provided by physicians who care for their patients in both ambulatory and hospital settings. Care is now increasingly divided between physicians specializing in hospital care (hospitalists) and ambulatory-based care primary care...

Health care spending varies widely across markets, yet there is little evidence that higher spending translates into better health outcomes, possibly due to endogeneity bias. The main innovation in this paper compares outcomes of patients who are exposed to different health care systems that...

Policymakers are increasingly interested in reducing healthcare costs and inefficiencies through innovative payment strategies. These strategies may have heterogeneous impacts across geographic areas, potentially reducing or exacerbating geographic variation in healthcare spending. In this...

There is considerable controversy about the causes of regional variations in health care expenditures. Using vignettes from patient and physician surveys linked to fee-for-service Medicare expenditures, this study asks whether patient demand-side factors or physician supply-side factors explain...

We study the role of physicians in driving geographic variation of US healthcare utilization. We estimate a model that separates variation in average utilization of Medicare beneficiaries due to physicians, non-physician supply side factors, and patient demand. The model is identified by...

We develop an equilibrium model of industrial structure in which the organization of firms is endogenous. Differentiated consumer products can be produced either by vertically integrated firms or by pairs of specialized companies. Production of each variety of consumer good requires a unique,...

We model the implications of the classical ideas that larger markets allow for a finer division of labor and this division feeds back into larger market size. Market size affects specialization due to firm-level increasing returns to scale arising from fixed costs of adopting...

The introduction of new technologies in agriculture can foster structural transformation by freeing workers who find occupation in other sectors. The traditional view is that this reallocation of workers towards manufacturing can lead to industrial development. However, when workers moving to...

We study how the inventive capability of a firm conditions its participation in a division of innovative labor. Capable firms are, by definition, able to invent; for them, external inventions substitute for their own R&D. However, external knowledge is an input into internal invention, and thus,...

This paper quantitatively assesses the world's changing economic geography and sectoral specialization due to global warming. It proposes a two-sector dynamic spatial growth model that incorporates the relation between economic activity, carbon emissions, and temperature. The model is taken to...