Limited Supply
Ban-It-Harderism in European Consumer Law: The Case of the French Influencer Law
Laura Aade & Catalina Goanta
Journal of Consumer Policy, December 2025, Pages 523-538
Abstract:
In June 2023, France adopted a new law to curb the negative impact of influencer marketing on its consumers. While it introduces some innovative provisions, the law mostly doubles down on legal prohibitions that could have been equally construed under existing consumer protection legislation. From this perspective, it can be argued that this law is an example of ban-it-harderism: a regulatory trend where lawmakers respond to perceived enforcement failures, not by addressing structural or institutional issues, but by enacting additional prohibitions that duplicate existing norms. Ban-it-harderism is problematic for at least two reasons. First, it often gives the false public impression that certain issues were not covered by regulation before the specific intervention. Second, it contributes to the overwhelming regulatory inflation seen at European and national levels on matters dealing with technology regulation and the digital market. This article discusses selected provisions from the French Influencer Law to contrast them with existing European consumer law and to critically reflect on its contributions to relevant legal frameworks.
Existential Risk and Growth
Philip Trammell & Leopold Aschenbrenner
Stanford Working Paper, December 2025
Abstract:
Technological development raises consumption but may pose existential risk. A growing literature studies this tradeoff in static settings where stagnation is perfectly safe. But if any risky technology already exists, technological development can also lower risk indirectly in two ways: by speeding (1) technological solutions and/or (2) a “Kuznets curve” in which wealth increases a planner’s willingness to pay for safety. The risk-minimizing technology growth rate, in light of these dynamics, is typically positive and may easily be high. Below this rate, technological development poses no tradeoff between consumption and cumulative risk.
U.S. Regulatory Delays in Construction Across Time
Sam Nak-Kyu Barnett
Princeton Working Paper, January 2026
Abstract:
Existing measures of the stringency of U.S. land use regulations are snapshots in time. To study the relationship between administrative barriers and housing affordability, I use permit-level data to construct a novel dataset of average annual delays for new residential construction permits in more than 100 U.S. cities, covering over 20 years. Average delays correlate positively and significantly with house prices across cities. Using a local projection specification with city fixed effects, a one-month increase in delays (approximately a standard deviation) is estimated to increase house prices two years later by about $25,000. Delays are negatively correlated with the electoral vote share of city council members, both in the cross section and dynamically, and relate closely with subindices of the 2018 Wharton Regulatory Land Use Survey Initiative (WRLURI). The above results are significant at the 0.05 level.
Legal Assistance for Evictions: Impacts, Mechanisms, and Demand
Aviv Caspi & Charlie Rafkin
Stanford Working Paper, January 2026
Abstract:
An active policy debate concerns whether to provide free legal counsel to tenants in eviction cases. We randomize provision of attorneys to tenants facing eviction in Memphis, Tennessee (N = 307 attorneys provided). Despite landlord-friendly eviction law, providing an attorney reduces tenant eviction judgment rates within 180 days by 23 percentage points (37%). However, attorneys’ effects persist only when they can connect tenants to other services. Once a concurrent emergency rental assistance program expires, effects on judgments at 180 days shrink by about 75% and are indistinguishable from zero. Incentivized surveys suggest tenants’ demand for an attorney is double attorneys’ price, and eight times attorneys’ implied impacts on tenants’ incomes via stopping evictions. This high willingness to pay does not appear to result from elicitation errors, misperceptions, or binding budget constraints. We contrast lawyers’ Marginal Value of Public Funds from using elicited willingness to pay (MVPF = 2.7 without rental assistance, ignoring impacts on landlords or general equilibrium) versus a standard calibrated approach (MVPF = 0.3) and discuss implications for the evaluation of policies involving in-kind goods.
The Downmarket Impact of New Multifamily Housing: Evidence from a Honolulu Condo Tower
Limin Fang, Emi Kim & Justin Tyndall
University of Hawaii Working Paper, November 2025
Abstract:
We test whether new condominium construction generates vacancies in a local housing market through induced moves. Using detailed address-history microdata, we track households who moved into a newly built 512-unit condominium tower in Honolulu, Hawai'i, which included both market-rate and income-restricted units. We identify prior addresses and follow vacancy chains across multiple rounds of moves. The vacated homes were substantially cheaper than the new units and spanned diverse locations and housing types. Income-restricted units produced fewer secondary vacancies, but those vacancies were concentrated at lower price points. Our results show that new condominium construction eases supply constraints and expands affordability in a local housing market, and the contrast between market-rate and income-restricted units has important implications for inclusionary zoning policies.
Beyond Sports Betting Legalization: Comparing Problem Gambling Risk Patterns in Legal and Illegal States
Tiange Xu, Joshua Grubbs & Shane Kraus
Journal of Gambling Studies, December 2025, Pages 1689-1701
Abstract:
The 2018 Supreme Court decision allowing state-level sports betting legalization in the United States has raised concerns about its impact on problem gambling risk. This study examined whether legal status predicts problem gambling severity scores while adjusting for demographic characteristics. Data were collected in March-April 2022 from sports bettors in states with legal (n = 974) and illegal (n = 307) sports betting, using the Problem Gambling Severity Index to assess risk levels. While legal status did not significantly predict problem gambling risk, demographic factors emerged as crucial predictors. Age and education consistently predicted risk across both regulatory contexts, with younger bettors and those with lower education showing greater vulnerability. However, other demographic patterns varied by context: females demonstrated higher risk in illegal states while no gender differences emerged in legal states, and single status predicted elevated risk only in legal jurisdictions. These findings indicate that sports betting policy considerations should extend beyond the simple decision to legalize or prohibit, to consider context-specific interventions based on demographic vulnerabilities.
Quantifying the Welfare Effects of Gentrification on Incumbent Low-Income Renters
Robert French, Ashvin Gandhi & Valentine Gilbert
University of Chicago Working Paper, January 2026
Abstract:
How does gentrification affect the welfare of incumbent residents of low-income neighborhoods? This paper investigates how low-income renters in gentrifying neighborhoods fare relative to renters in neighborhoods in the same metro area that stay poor. We link person-level administrative US Census data to construct an annual panel that tracks the earnings, workplaces, and residential addresses of over 1 million US low-income urban renter households from 2000 to 2019. We use these data to estimate a dynamic structural model of residential and workplace choice. We identify our model with labor demand shocks to potential commuting destinations constructed with geocoded establishment-level business data. We find that — because low-income renters are highly mobile within cities — gentrification affects incumbent renters primarily by changing the characteristics of other neighborhoods in their choice sets. Our results imply that where low-income renters lived within US metro areas mattered comparatively less than which US metro areas they lived.
The Emerging Market for Intelligence: Pricing, Supply, and Demand for LLMs
Mert Demirer et al.
NBER Working Paper, December 2025
Abstract:
We document six facts about the structure and dynamics of the LLM market using API usage data from OpenRouter and Microsoft Azure. First, we show rapid growth in the number of models, creators, and inference providers, driven by open-source entrants. Second, we show price declines and persistent price heterogeneity across and within intelligence tiers, with open-source models being 90% cheaper than comparable closed-source models of the same intelligence. Third, we document market dynamism, with frequent turnover among leading models and creators. Fourth, we present evidence of horizontal and vertical differentiation, with no single model dominating across use cases, and demand for intelligence varying widely across applications. Fifth, we estimate preliminary short-run price elasticities just above one, suggesting limited scope for Jevons-Paradox effects. Finally, we show that although the share of firms that use multiple models increased over time, most firms concentrate their use on a single model, consistent with experimentation rather than persistent reliance on multiple models.
Rising Concentration of Household Shopping, Superstar Firms, and the Implications for Retail Markups
Justin Leung & Zhonglin Li
American Economic Journal: Applied Economics, January 2026, Pages 160-194
Abstract:
This paper documents an increase in the concentration of household shopping in the United States retail sector from 2004 to 2019. Despite a growing number of stores, households visit fewer stores, do more one-stop shopping, and increasingly shop at different retailers from each other. We find that the increasing availability of superstar retailers, the rise in product variety within stores, and the rise of online shopping contribute to these trends. We explore how these trends are linked with rising retail markups. Our calibration suggests a 5–10 percentage point increase in aggregate retail markups during this period.
Technology M&As and Knowledge Diffusion
Zili Yang
University of Southern California Working Paper, January 2026
Abstract:
This paper examines how technology mergers and acquisitions (tech M&As) affect the diffusion of target firms’ pre-acquisition innovations in the United States. Using US patent and M&A data from 1980 to 2021. This study employs a difference-in-differences approach comparing successful acquisitions with exogenously failed deals; it finds that tech M&As significantly increase external diffusion of targets' technologies, as measured by patent citations, with effects concentrated within the acquirer's industry. Tech M&As do not diminish young firms' ability to cite and build upon acquired targets' patents, contradicting concerns about innovation foreclosure. To interpret these findings and quantify aggregate implications, I develop an idea flow model where firms improve productivity by choosing innovation intensity based on potential targets' technologies, with acquisitions affecting both the innovation step size in learning from targets and the cost of accessing them. The model, calibrated to the empirical estimates and US innovation data, reveals that doubling the 2015 tech M&A rate would increase annual productivity growth by five hundredths of a percentage point, with the diffusion channel contributing 40% of this increase. Surprisingly, relaxing restrictions on post-acquisition knowledge appropriation yields negligible growth effects: reduced spillovers from acquired targets are offset by increased innovation using independent technologies as acquisition values rise. These findings underscore the importance of incorporating diffusion effects and general equilibrium forces into antitrust policy for tech M&As.
The Effects of Regulating Greenwashing: Evidence from Europe’s Sustainable Finance Disclosure Regulation (SFDR)
Hunt Allcott et al.
NBER Working Paper, January 2026
Abstract:
We examine the impact of the European Union’s Sustainable Finance Disclosure Regulation (SFDR) on mutual fund flows and investment sustainability. The SFDR classifies funds into three categories to promote transparency and curb greenwashing: those with a sustainable investment objective (Article 9 or “dark green”), those that promote environmental characteristics (Article 8 or “light green”), and others (Article 6). Using a difference-in-differences design, we find that the SFDR had little effect on fund flows or portfolio sustainability. The disclosures were ineffective in part because they offered little new or clear information beyond what investors could already infer from fund names and mandates. In an experimental setting, we show that the current disclosures have minimal impact on investor decisions, but making the information more intuitive could improve the regulation’s effectiveness.
The Equilibrium Impacts of Broker Incentives in the Real Estate Market
Gi Heung Kim
Boston College Working Paper, January 2026
Abstract:
Commission rates for housing transactions are twice as high in the United States than in other countries. Policymakers have raised concerns that the practice of sellers offering buyers’ brokers commissions can lead to high commissions and harm consumers. This paper empirically examines the equilibrium impacts of a proposed policy called “decoupling,” which would require buyers and sellers to each pay their respective brokers. I develop a structural model integrating buyers, sellers, and brokers to characterize the equilibrium house prices, com- missions, and to assess the welfare impacts of the policy. I estimate the model with rich observed heterogeneity and credible sources of identifying variation using shifters of house prices and commissions. I find that decoupling reduces commissions paid by 53%, as sellers no longer have to offer high commissions to attract buyers, and brokers compete for price-sensitive buyers. Sellers and buyers experience a surplus gain of 4% of the total transaction value from having higher net proceeds than the status quo. I find notable surplus gains for buyers across income groups as sellers pass through part of their commission savings to house prices.