Steve Tadelis - Working Papers
Digital Advertising and Market Structure:
Implications for Privacy Regulation
(with Nils Wernerfelt, Utsav Manjeer, Zarak Sohail, and Daniel Deisenroth
), February 2026
ABSTRACT
We study how changes in the effectiveness of targeted digital advertising shape firm
behavior and product-market outcomes. We leverage the introduction of Apple’s App
Tracking Transparency (ATT) framework, which limited online advertisers’ access to user
data and thus substantially reduced their advertising effectiveness. Using proprietary
advertiser-level data from Meta and industry-level outcomes from the Bureau of Labor
Statistics, we show that greater exposure to the ATT shock led to lower ad spend, fewer
establishments, and higher product prices. The findings suggest that digital advertising
primarily expands markets and that privacy policies can have unintended consequences
on product market competition. JEL classifications: D40, L10, L51, M37
view a
PDF file
Learning, Sophistication, and the Returns to Advertising: Implications for Differences in Firm Performance
(with Christopher Hooton, Utsav Manjeer, Daniel Deisenroth, Nils Wernerfelt, Nick Dadson, and Lindsay Greenbaum
), April 2023
ABSTRACT
Why do establishments exhibit wide variation in their productivity and profitability? Can variation in returns to advertising help answer this question? We present results from a large field experiment on Facebook and Instagram that documents variance in advertisersâ ability to generate returns to advertising. We focus on campaigns aimed at boosting sales and tie advertising expenses to revenues for each advertiser. We find that spending on advertising led to significant increases in revenues, number of purchases, number of purchasers, and number of conversions. The heterogeneity in these results by expenditure, age, and engagement documents patterns consistent with learning by doing and variance in how sophisticated advertisers are. Advertisers who engage in more learning activities and more sophisticated data collection exhibit the highest returns and are more likely to continue their activities over time, suggesting that differences in advertising effectiveness may account for some of the variance in productivity across firms.
view a
PDF file
The Economics of Algorithmic Pricing: Is collusion really inevitable?
(with Kai-Uwe Kühn), December 2018
ABSTRACT
Concerns have recently been raised that rapid technological development in artificial intelligence and ecommerce would help facilitate collusive behavior and threaten competition. We build on several strands of research in economics to assess whether algorithmic pricing poses new threats to competition, and, more importantly, whether new enforcement tools are needed to respond to these potential threats. We argue that the concerns raised are overly aggressive because of a basic and fundamental difficulty of achieving coordination in real-world pricing games, which cannot be easily overcome by algorithms. We further argue that current policy and enforcement tools seem broadly adequate to address the threats of collusion that can be expected to be present when pricing algorithms are used, at least until more rigorous research shows otherwise. JEL classifications: D43, K21, L13, L41.
view a
PDF file
The Power of Shame and the Rationality of Trust
March 2011
ABSTRACT
A mounting number of studies suggest that individuals are not selfish, which perhaps
explains the prevalence of trust among strangers. Models of players who care about
their opponents' payoffs have been used to rationalize these facts. An alternative
motive is that players care directly about how they are perceived by others. I propose
and implement an experimental design that distinguishes perception motives from payoff
motives. Participants not only exhibit concerns for perception, but they seem strategically
rational by anticipating the change in behavior of their opponents. The approach can
explain previously documented behaviors, both in the lab and in the field, and can shed
light on some determinants of trust. JEL classifications C72, C91, D03, D82
view a
PDF file
|