I am an assistant professor in Wharton's Business Economics and Public Policy group working on empirical
industrial organization, with a focus on antitrust and the digital economy. Before Wharton, I was a
Postdoctoral Researcher at Microsoft Research New England, and obtained my PhD in Economics at Princeton
University.
This study evaluates the impact of generative AI on software developer productivity by analyzing data from
three randomized controlled trials conducted at Microsoft, Accenture, and an anonymous Fortune 100
electronics manufacturing company. These field experiments, which were run by the companies as part of
their ordinary course of business, provided a randomly selected subset of developers with access to GitHub
Copilot, an AI-based coding assistant that suggests intelligent code completions. Though each separate
experiment is noisy, combined across all three experiments and 4,867 software developers, our analysis
reveals a 26.08% increase (SE: 10.3%) in the number of completed tasks among developers using the AI tool.
Notably, less experienced developers showed higher adoption rates and greater productivity gains.
This paper investigates concerns that vertically integrated platforms like Amazon steer demand towards their own offers via algorithmic prominence, potentially harming consumers. On Amazon, for each product, the Buybox prominence algorithm selects one seller to feature, influencing which offers consumers consider. Using novel Amazon sales and Buybox (prominence) data, we estimate a structural model capturing the effects of such algorithmic prominence on consumer choices, seller pricing, and entry. We find that the platform can indeed steer demand as 95% of consumers consider only the Buybox offer. The Buybox is highly price-elastic (−21), but skews towards Amazon’s own offers, which are featured as frequently as observably similar offers priced 5% cheaper. Still, as consumers prefer these offers, this skew does not amount to self-preferencing in the sense of harming consumers: consumer surplus is roughly maximized at the estimated Amazon Buybox advantage, which balances higher prices against showing consumers their preferred offers.
We study the forces behind Google’s large web-search market share. We develop a demand model with switching costs, quality beliefs, and inattention, and estimate it using a field experiment. We find that (i) requiring active choice barely increases Bing’s market share; (ii) Google users paid to try Bing update positively about its quality and many prefer to continue using it; (iii) many Google users defaulted into Bing do not switch back, consistent with inattention. Counterfactuals suggest that eliminating demand frictions doubles Bing’s market share. Successful remedies expose users to alternative search engines, while data sharing mandates have small effects.
We develop a method for detecting cartels in multistage auctions. Our approach allows a firm to be
collusive when facing members of its cartel yet competitive when facing others. Intuitively, as initial
bids are shaded, close initial bids not only imply similar costs but also provide an incentive to
undercut. We detect firm pairs that ignore this incentive when facing each other. Our algorithm predicts
Ukraine’s Antimonopoly Committee sanctions, yet uncovers additional collusion: 2,371 collusive firms
participate in 19% of auctions, increasing costs by 2.12%. Cartels typically comprise just two members,
and members often share the same ZIP code.
As the economy digitizes, menu costs fall, and firms can more easily monitor prices. These
trends have led to the rise of automated pricing (and re-pricing) tools. We employ a novel
e-commerce dataset to examine the effect of algorithmic pricing in the wild. Evidence from an
event study suggests that firms that start employing repricing tools drop their prices by 16.7%,
with market prices falling by 9.5%. However, algorithmic pricing companies have developed
‘resetting’ strategies (which regularly raise prices in the hope that competitors will follow) in
order to avoid stark Bertrand-Nash competition. We find that these strategies are effective at
coaxing competitors to raise their prices: when a resetting strategy is adopted, both competitor
prices and market prices eventually increase by 8%. While the resulting patterns of cycling
prices are reminiscent of Maskin-Tirole’s Edgeworth cycles, a model of equilibrium in delegated
strategies fits the data better. This model suggests that the average price over the cycle will be
the monopoly price. Moreover, if the available repricing technologies remain fixed, cycling and
prices could rise significantly. However, cycling is still relative rare in the data.
We analyze a vote-buying setup where a committee votes on a proposal important to the vote buyer. We
characterize the cheapest combination of bribes that guarantees the proposal's passing in different voting
environments. We find that the vote buyer publicly offers small bribes to a large supermajority of members
for both simultaneous and sequential votes. Each member accepts because he anticipates that the proposal
will pass regardless of his vote. We discuss the committee design that maximizes capture cost: combining
demanding majority requirements with diversity among members makes the committee more expensive. In small
committees, sequential voting increases cost, but the opposite is true for large committees. On the other
hand, additional members and transparent voting rules lower the cost.
(PDF of Old Version with
Additional Examples.)