Liad Wagman

The Hart-Scott-Rodino (HSR) Act requires firms to notify the U.S. antitrust agencies of acquisitions that exceed size thresholds. We study the economic consequences of the 2000 HSR Amendments, effective in 2001, which raised the minimum reporting threshold from $15 to $50 million, as adjusted, and removed the percentage-of-shares trigger, exempting many smaller transactions from review. Using SDC/Refinitiv transaction data, annual HSR reports, and Census Business Dynamics Statistics, we construct an industry-level measure of exposure to the reform and compare more-and less-exposed industries over the following two decades. We document three stylized facts: the HSR reform is associated with a shift in the composition of recorded acquisitions toward larger, same-industry, and repeated-acquirer deals; these responses differ sharply between goods-producing and service industries; and so do the accompanying changes in industry and labor-market dynamics.

Drug enforcement activities are often shared between national and subnational government agencies. In the United States, federal law enforcement agencies have actively partnered with local agencies to prosecute drug crimes using federal and state court-issued wiretap orders. We theorize and provide evidence on how federal involvement in narcotics cases influences prosecutorial outcomes. We show that a greater number of federal agency field offices is associated with fewer arrests made from state wiretap orders, while leading to more convictions secured from federal wiretap orders. Thus, federal institutions may influence how criminal cases are handled across national and subnational levels.

This paper studies a platform’s incentive to disclose and disseminate consumer reviews about the vicinity safety of short-term rental listings.

Using a unique dataset on Software Development Kits (SDKs), we study SDK usage in Android mobile apps before and after the European Union implemented the General Data Protection Regulation (GDPR) in May 2018. In the raw data, Android apps in both the US and five major European countries (EU5) increased SDK usage after the GDPR, despite the GDPR's heuristic concerning data minimization. However, relative to US-only apps, we find that EU5-only apps reduce the number of non-Google SDKs by 1.3% after GDPR's rollout. This small and marginally significant result is driven by non-top-ranked apps and by both SDKs involving sensitive data and SDKs involving non-sensitive data. In contrast, apps that multihome in the US and EU5 reduce SDK usage by 6.3% after the GDPR relative to US-only apps. This larger and highly significant result likely occurs due to restrictions on cross-border data transfers and because SDK usage is less correlated with app performance for multihoming apps.

We examine how public firms listed in North American stock exchanges acquire technology companies during 2010–2020. Combining data from Standard and Poor's (S&P), Refinitiv, Compustat, and Center for Research in Security Prices, and utilizing a unique S&P taxonomy that classifies tech mergers and acquisitions (M&As) by tech categories and business verticals, we show that 13.1% of public firms engage in any tech M&A in the S&P data, while only 6.75% of public firms make any (tech or nontech) M&A in Refinitiv. In both data sets, the acquisitions are widespread across sectors of the economy, but tech acquirers in the S&P data are on average younger, more investment efficient, and more likely to engage in international acquisitions than general acquirers in Refinitiv. Within the S&P data, deals in each M&A‐active tech category tend to be led by acquirers from a specific sector; the majority of target companies in tech M&As fall outside the acquirer's core area of business; and firms are, in part, driven to acquire tech companies because they face increased competition in their core areas.

We examine several ways in which the U.S. Federal Trade Commission’s antitrust enforcement has changed under Lina Khan, including policy changes and proposed technology-related rulemakings, and relevant recent court cases and academic research. We comment on the potential consequences of these changes for both the market and for the Commission’s reputation as a public institution.

We provide an in-depth examination of short-term rental regulation in Chicago. While many cities choose between outright bans or laissez-faire strategies concerning short-term rentals, Chicago pioneered a middle ground ordinance, aiming to accommodate this market while addressing various concerns. Our analysis reveals a 16.4% decline in active listings following the ordinance, but only after the city began receiving direct data feeds from intermediary platforms. We demonstrate the effects differ for commercial operators and individual hosts. The overall decline resulted in a substantial drop in Airbnb revenues as well as in tax revenues for the city, county and state from short-term rentals, and benefited hotels. Despite minimal effects on crime citywide, we find a localized reduction in burglaries near buildings that prohibit short-term rentals as part of a new capability introduced by the ordinance.

Consumer reviews, especially those expressing concerns of product quality, are crucial for the credibility of online platforms. However, reviews that criticize a product or service may also dissuade buyers from using the platform, creating an incentive to blur the visibility of critical reviews. Using Airbnb and official crime data in five major US cities, we find that both reviews and self experiences concerning the safety of a listing's vicinity decrease guest bookings on the platform. Counterfactual simulations suggest that a complete removal of vicinity safety reviews (VSR) would hurt guests but increase revenues from reservations on Airbnb, with positive sorting towards listings formerly with VSR. Conversely, incorporating VSR in a listing's overall ratings or highlighting VSR could generate opposite effects. Either way, the interests of consumers are not always aligned with the interests of a revenue-centric platform. Because VSR are more closely correlated with official crime statistics in low-income and minority neighborhoods, our findings suggest that suppressing or highlighting VSR would have different effects on different neighborhoods.

Consumer reviews, especially those expressing concerns of product quality, are crucial for the credibility of online platforms. However, reviews that criticize a product or service may also dissuade buyers from using the platform, creating an incentive to blur the visibility of critical reviews. Using Airbnb and official crime data in five major US cities, we find that both reviews and self experiences concerning the safety of a listing's vicinity decrease guest bookings on the platform. Counterfactual simulations suggest that a complete removal of vicinity safety reviews (VSR) would hurt guests but increase revenues from reservations on Airbnb, with positive sorting towards listings formerly with VSR. Conversely, incorporating VSR in a listing's overall ratings or highlighting VSR could generate opposite effects. Either way, the interests of consumers are not always aligned with the interests of a revenue-centric platform. Because VSR are more closely correlated with official crime statistics in low-income and minority neighborhoods, our findings suggest that suppressing or highlighting VSR would have different effects on different neighborhoods. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.