This paper examines the evolving structure and competition dynamics of the rapidly growing market for foundation models, with a focus on large language models (LLMs). We describe the technological characteristics that shape the AI industry and have given rise to fierce competition among the...

We document the effects of a comprehensive set of US retail mergers. On average, prices increase by 1.5% and quantities decrease by 2.3%, with significant heterogeneity in outcomes across mergers. Price changes correlate with the screens codified in the Horizontal Merger Guidelines. Through a...

This paper uses an aggregative games framework to predict consumer welfare when market structure is endogenously determined. Our main results characterize mergers whose synergies reduce consumer welfare by inducing rivals to exit. The conditions under which such mergers arise are broad,...

We hand-collect and standardize information describing all 3,055 antitrust lawsuits brought by the Department of Justice (DOJ) between 1971 and 2018. Using restricted establishment-level microdata from the U.S. Census, we compare the economic outcomes of a non-tradable industry in states...

Antitrust enforcement in the United States has declined since the 1960s. Building on several new datasets, we argue that this decline did not reflect a popular demand for weaker enforcement or any other kind of democratic sanction. The decline was engineered by unelected regulators and judges...

We build a model of online behavioral manipulation driven by AI advances. A platform dynamically offers one of n products to a user who slowly learns product quality. User learning depends on a product's "glossiness,' which captures attributes that make products appear more attractive than they...

Open source is key to innovation, but we know little about how to incentivize it. In this paper, we examine the impact of a program providing monetary incentives to motivate innovators to contribute to open source. The Sponsors program was introduced by GitHub in May 2019 and enabled...

Using data on Software Development Kits (SDKs), we study SDKs in Android apps vis-à-vis the adoption of the General Data Protection Regulation (GDPR) by the European Union in May 2018. Relative to US-only apps, the number of non-Google SDKs used per app in 5 major European countries (EU5)...

Retailers are increasingly selling goods and services via subscriptions instead of spot markets. In this paper, we study one benefit to the retailer of selling subscriptions: the possibility that - presumably because of inattention or inertia - consumers continue to pay for subscriptions after...

High-speed internet has increased the amount of information available in health care markets. Online information may improve health outcomes if it reduces information frictions and helps patients choose higher quality providers or causes providers to improve quality. We examine how health...