National Bureau of Economic Research

A growing fraction of US medical care is delivered through integrated healthcare systems that include many medical providers, ranging from primary care physicians to acute care hospitals. A team led by Research Associate David Cutler of Harvard University and Nancy Beaulieu of Harvard Medical School, supported by a multiyear grant to the NBER from the federal Agency for Healthcare Research and Quality, has studied the rise of healthcare systems and their impact on the delivery of care. The findings, just published in the Journal of the American Medical Association, suggest that the quality of care is marginally better when provided through a system, but the cost is substantially greater.

Unicorns — startup businesses that are valued at at least $1 billion before going public — essentially did not exist before the 2000s. Their numbers have recently surged. These firms break with the traditional startup trajectory by going public later and at valuations far above those of other startups. They also attract late-stage funding not from venture capitalists but from large institutional investors who are more patient, more open to raising the large sums necessary for the firm to keep growing, and more willing to allow company founders and initial shareholders to cash out before the initial public offering (IPO). 

In The Unicorn Puzzle (NBER Working Paper 30604), Daria Davydova, Rüdiger Fahlenbrach, Leandro Sanz, and René M. Stulz find that of the 639 US startup...

When colleges and universities reopened in the fall of 2021, only 47 percent of 18-to-24-year-olds in the United States were fully vaccinated against COVID-19. At institutions that required students to be vaccinated, however, the vaccination rates were much higher. In The Effect of Vaccine Mandates on Disease Spread: Evidence from College COVID-19 Mandates (NBER Working Paper 30303), Riley K. Acton, Wenjia Cao, Emily E. Cook, Scott A. Imberman, and Michael F. Lovenheim show that the health benefits of these…

The US is one of the few countries worldwide that does not have a federal paid family leave (PFL) policy. In the absence of a federal policy, some states have adopted PFL policies, starting with California in 2004 and now including 11 states and the District of Columbia. These PFL policies provide paid time off for workers who need to care for a newborn or a newly adopted child (parental leave) or for an ill or temporarily disabled family member (caregiving leave). 

While there is extensive research on the use of PFL for parental leaves, based on the experience of California and other early adopting states, much less is known about the use of PFL for caregiving leaves. The imbalance in empirical evidence for the two types of leaves may contribute to the higher level of public support and greater consensus among…

The importance of innovation to job creation and economic growth — especially in young, high-growth firms — is widely accepted among economists as well as members of the business and policy communities. There is also a recognition that, at least at some times or in certain settings, the private sector underinvests in innovation, creating an opportunity for the public sector to step into the breach.

The longstanding problem is how. What tools are most effective?

There are myriad opportunities for government programs to fail. For example, if a program subsidizes only the “best projects,” those that would likely have gone forward with private capital regardless of…

Startups located in coworking hubs can benefit from knowledge spillovers from their startup neighbors.  In (Co-)Working in Close Proximity: Knowledge Spillovers and Social Interactions (NBER Working Paper 30120), Maria P. Roche, Alexander Oettl,  and Christian Catalini find that knowledge spillovers are greatest among startup workers who socialize but are in moderately dissimilar enterprises.

The researchers studied one of the five largest technological coworking hubs in the nation, where 251 startups were randomly assigned office space in a five…