Broadening Focus: Spillovers and the Benefits of Specialization in the Hospital Industry

by Jonathan R. Clark & Robert S. Huckman

Overview — What is the optimal scope of operations for firms? This question has particular relevance for the US hospital industry, because understanding the effects of focus and spillovers might help hospitals determine how they should balance focusing in a single clinical area with building expertise in related areas. While some scholars argue that narrowing an organization's set of activities improves its operational efficiency, others have noted that seemingly unfocused operations perform at a high level and that a broader range of activities may in fact increase firm value. This study by HBS doctoral student Jonathan Clark and professor Robert Huckman highlights the potential role of spillovers—specifically complementary spillovers—in generating benefits from focus at the operating unit level. Key concepts include:

Hospitals devoting a greater portion of their business to treating patients in related service categories (i.e., those with the potential for knowledge spillovers) experience higher returns to specialization in a focal service.
Ultimately, these results provide a potential explanation for why there might be decreasing returns to focusing an organization on a single operating activity (or narrow set of activities), especially when it is possible to invest in other activities that complement the organization's area of concentration.

Author Abstract

The long-standing argument that focused operations outperform others stands in contrast to claims about the benefits of broader operational scope. The performance benefits of focus are typically attributed to reduced complexity, lower uncertainty, and the development of specialized expertise, while the benefits of greater breadth are linked to the economies of scope achieved by sharing common resources, such as advertising or production capacity, across activities. Within the literature on corporate strategy, this tension between focus and breadth is reconciled by the concept of related diversification (i.e., a firm with multiple operating units, each specializing in distinct but related activities). We consider whether there are similar benefits to related diversification within an operating unit and examine the mechanism that generates these benefits. Using the empirical context of cardiovascular care within hospitals, we first examine the relationship between a hospital's level of specialization in cardiovascular care and the quality of its clinical performance on cardiovascular patients. We find that, on average, focus has a positive effect on quality performance. We then distinguish between positive spillovers and complementarities to examine the following: (1) the extent to which a hospital's specialization in areas related to cardiovascular care directly impacts performance on cardiovascular patients (positive spillovers) and (2) whether the marginal benefit of a hospital's focus in cardiovascular care depends on the degree to which the hospital "co-specializes" in related areas (complementarities). In our setting, we find evidence of such complementarities in specialization.