Larger matching markets offer more opportunities to find suitable partners, but a platform that charges for each match may respond to these opportunities by raising its fees. We analyze how a monopoly platform sets match-contingent fees in a two-sided market where the outcome is a stable matching. In any finite market, the expected number of stable matches responds less than proportionally to mutual acceptability. In the large-market approximation this response falls as the market becomes thicker and as the long side grows, so the optimal fee rises as the market grows. We then characterize the exact revenue-maximizing fee in large markets. When match values have heavy, regularly varying tails, the platform leaves a positive fraction of the short side unmatched, regardless of how large the market becomes, and its fee grows without bound. Conversely, when values have light tails, the platform’s fee approaches the highest level the value distribution admits, and the fraction of the short side that remains unmatched tends to zero. Market growth therefore need not eliminate the exclusion induced by platform pricing.

School choice mechanisms determine not only where students study but also who their classmates are. Deferred acceptance (DA) protects families in this regard through local non-bossiness: a student who keeps her school cannot alter its cohort by misreporting her ranking. This paper examines whether the protection persists under reforms designed to correct DA’s inefficiency, and concludes that it does not. Any mechanism that yields a Pareto improvement over DA whenever one exists fails to be locally non-bossy in every problem with a separating double rotation, a configuration of priorities and capacities that arises under random priorities in most large markets. Efficiency-adjusted deferred acceptance loses the protection once two identified students consent and, in large markets, with probability approaching one when a fixed fraction of students chosen independently of priorities consents. We also show how the consequences of this manipulation for segregation depend on how student types relate to priorities.

with Stephany Griffith-Jones, Catalina Estefó, and Max Gondonneau

This paper quantifies the impact of non-resident Non-Deliverable Forward (NDF) flows on the Chilean peso using daily administrative data. Exploiting the structural break caused by the 2020–2021 pension fund withdrawals, we document a critical regime shift. We find that the retrenchment of local institutional investors eroded market depth, leading to a heightened, nonlinear sensitivity to short-term speculative flows. Post-withdrawal, these offshore positions significantly amplify depreciation and volatility. Our findings underscore the financial stability risks arising when domestic liquidity buffers are compromised, presenting key challenges for monetary policy and regulatory design.

with Juan Pablo Torres-Martínez

In a class of three-sided matching problems that always have stable solutions, we show that no stable mechanism is strategy-proof for those who internalize the trilateral structure in their preferences. Furthermore, strong restrictions on preferences are needed to ensure that stability and one-sided strategy-proofness are compatible for all sides of the market. These results are related to the incompatibility between stability and one-sided group strategy-proofness in two-sided markets.

with Juan Pablo Torres-Martínez

Journal of Combinatorial Optimization, 45, Article 62, 2023

We reexamine the existence of stable solutions in a class of three-sided matching problems previously studied by Zhang and Zhong (2021). The sets of participants are U, V, and W. Agents in U have strict preferences defined on V, agents in V have strict preferences defined on W, and agents in W have strict preferences defined on U × V. In this framework, we show that a weakly stable matching may not exist.

with Stephany Griffith-Jones

ODI Global, April 2026 (Link)

with Mario Giarda and Stephany Griffith-Jones

In How Can Central Banks Take Account of Differences across Households and Firms for Monetary Policy?, BIS Papers No. 147, June 2025 (PDF)

with Stephany Griffith-Jones

Central Bank of Chile Working Papers N983, October 2024 (PDF)

with S. Baudocco, G. Contreras, J. Guerra, and S. Griffith-Jones

Central Bank of Chile Blogs, September 2024 (Link)

with P. Concha, M. García, E. Luttini, and J. E. Rishmawi

Monetary Policy Report, Central Bank of Chile, March 2023 (Link)