We present a new model of competition between digital media platforms with targeted advertising. The model adds new insights around how user heterogeneity and overlap, along with user and advertiser substitution patterns, determine equilibrium ad load. We apply the model to evaluate the proposed...

We estimate the effect of competition on incumbent firm pricing by using high frequency price data and the precise geographic location for all gas stations in California. Using an event study design, we find that the entry of a new station is associated with a 2.5 cent decrease in prices at...

We measure the real effects of private equity buyouts on worker outcomes by building a new database that links transactions to matched employer-employee data in the United States. To guide our empirical analysis, we derive testable implications from three theories in which private equity...

This paper empirically analyzes the effects of mergers between complementary firms on competition and pricing. As these non-horizontal mergers have become more common, there is increasing interest in evaluating both potential efficiencies such as eliminating double marginalization and potential...

While numerous papers document the effects of mergers on cost and quality, the effects of hospital mergers on access to care are less certain. Merging hospitals may limit access by closing one of the affected hospitals or eliminating individual service lines. However, hospital systems may have...

Fake product reviews--and the manipulation of reputation systems by sellers more broadly--are a widespread issue for two-sided platforms. We study two primary channels through which such manipulation can affect market outcomes: (i) creating misinformation about the reviewed product, and (ii)...

We present new facts about the largest American companies over the past century. In manufacturing, top firms in the 1910s, 1950s, and 2010s predominantly date back to around 1900. Even as this special generation persists, turnover among top firms has been substantial. In contrast, in retail and...

Solving complex problems- in medicine, engineering, and other technological domains- often requires exploring multiple approaches, particularly when significant uncertainty exists about which one will lead to success. Conventional wisdom assumes that having many experimenters independently...

We present several empirical facts about trends in marketing investment in the US. We also present estimates of the private value of brands to firms and aggregate intangible brand capital stocks created by these investments. These investments include the creation and maintenance of a brand name...

In this paper we provide a methodology that jointly studies production and demand for multi-product firms using detailed firm-product level data from Denmark. We estimate marginal cost by combining production function estimation with a cost function that allows for quasi-fixed inputs. We use a...