National Bureau of Economic Research

In a “rollup,” an outside investor consecutively acquires many of the small firms operating in a particular local market, consolidating them into a single large firm. Unlike mergers, which involve only two firms and trigger regulatory attention when the firms collectively exceed a certain size, rollups have flown under the antitrust radar until a recent Federal Trade Commission (FTC) case targeting a rollup of anesthesia practices in Texas. Rollups have become increasingly important, particularly in the healthcare industry.

In Painful Bargaining: Evidence from Anesthesia Rollups (NBER Working Paper 33217), Aslihan Asil, Paulo Ramos, Amanda Starc, and Thomas G. Wollmann study the competitive effects of the rollups...

The rapid advancement of artificial intelligence (AI) may usher in the most significant economic transformation since the Industrial Revolution. For nearly a decade, as I witnessed the continuous progress in deep learning, I have been studying the economics of transformative AI — how our economy may be transformed as AI systems advance toward mastering all forms of cognitive work that can be performed by humans, including new tasks that don’t even exist yet. The prospect of understanding the strange new world we will inhabit when transformative AI is developed has felt both intellectually urgent and personally meaningful to me as a father of two young children.

Today, AI systems are approaching and exceeding human-level performance in many domains, and it looks increasingly like our world will be transformed before…

In How Do Economic Conditions Affect Earnings and Return to Disability Programs for Beneficiaries Whose Benefits Were Terminated? (NBER RDRC Paper NB22-03), Jeffrey Hemmeter, Kathleen Mullen, and Stephanie Rennane find that individuals whose benefits end due to medical improvement during an economic downturn earn less in the short run and are more likely to reapply for benefits within five years than those...

Tiny, inhalable particles known as fine particulate matter (PM2.5) are a primary component of wildfire smoke and are detrimental to human health. Since smoke can drift hundreds of miles from its source, exposure to these pollutants is widespread: wildfire smoke accounts for about 18 percent of the ambient PM2.5 concentrations affecting the US population. 

In The Nonlinear Effects of Air Pollution on Health: Evidence from Wildfire Smoke (NBER Working Paper 32924), Nolan H. Miller, David Molitor, and Eric Zou leverage variation in the location of wildfire smoke plumes across counties and over time to show that…

Immigrants to the US are more entrepreneurial than the native population and overrepresented among high-growth startups and venture-backed tech firms. In Immigrant Entrepreneurship: New Estimates and a Research Agenda (NBER Working Paper 32400), Saheel Chodavadia, Sari Pekkala Kerr, William Kerr, and Louis Maiden use business surveys and administrative employment records to provide new evidence on the prevalence and predictors of immigrant...