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I am an economic theorist with broad interests.
I work as an associate professor at Oxford & Nuffield College.
You can reach me at <firstname.lastname@economics.ox.ac.uk>.
CV


Published & forthcoming papers:

Agenda-manipulation in ranking with Gregorio Curello
Review of Economic Studies, 2023
[supplement]  [25min video & slides]  [60min slides]
AbstractWe study the susceptibility of committee governance (e.g. by boards of directors), modelled as the collective determination of a ranking of a set of alternatives, to manipulation of the order in which pairs of alternatives are voted on—agenda-manipulation. We exhibit an agenda strategy called insertion sort that allows a self-interested committee chair with no knowledge of how votes will be cast to do as well as if she had complete knowledge. Strategies with this ‘regret-freeness’ property are characterised by their efficiency, and by their avoidance of two intuitive errors. What distinguishes regret-free strategies from each other is how they prioritise among alternatives; insertion sort prioritises lexicographically.

Slow persuasion with Matteo Escudé
Theoretical Economics, 2023
[supplement]
AbstractWhat are the value and form of optimal persuasion when information can be generated only slowly? We study this question in a dynamic model in which a ‘sender’ provides public information over time subject to a graduality constraint, and a decision-maker takes an action in each period. Using a novel ‘viscosity’ dynamic programming principle, we characterise the sender’s equilibrium value function and information provision. We show that the graduality constraint inhibits information provision relative to unconstrained persuasion. The gap can be substantial, but closes as the constraint slackens. Contrary to unconstrained persuasion, less-than-full information may be provided even if players have aligned preferences but different prior beliefs.

The converse envelope theorem
Econometrica, 2022
[supplement]  [10min video & slides]  [45min slides]
AbstractI prove an envelope theorem with a converse: the envelope formula is equivalent to a first-order condition. Like Milgrom and Segal’s (2002) envelope theorem, my result requires no structure on the choice set. I use the converse envelope theorem to extend to general outcomes and preferences the canonical result in mechanism design that any increasing allocation is implementable, and apply this to selling information.

Strictly strategy-proof auctions with Matteo Escudé
Mathematical Social Sciences, 2020
[published version]
AbstractA strictly strategy-proof mechanism is one that asks agents to use strictly dominant strategies. In the canonical one-dimensional mechanism design setting with private values, we show that strict strategy-proofness is equivalent to strict monotonicity plus the envelope formula, echoing a well-known characterisation of (weak) strategy-proofness. A consequence is that strategy-proofness can be made strict by an arbitrarily small modification, so that strictness is ‘essentially for free’.


Working papers:

The comparative statics of persuasion with Gregorio Curello
[60min video & slides]
AbstractIn the canonical persuasion model, comparative statics has been an open question. We answer it, delineating which shifts of the sender’s interim payoff lead her optimally to choose a more informative signal. Our first theorem identifies an ordinal notion of ‘increased convexity’ that we show characterises those shifts of the sender’s interim payoff that lead her optimally to choose no less informative signals. To strengthen this conclusion to ‘more informative’ requires further assumptions: our second theorem identifies the necessary and sufficient condition on the sender’s interim payoff, which strictly generalises the ‘S’-shape commonly imposed in the literature.

Comparative statics with adjustment costs and the le Chatelier principle with Eddie Dekel & John Quah
[60min slides]
AbstractWe develop a theory of monotone comparative statics in the presence of adjustment costs. We show that comparative-statics conclusions may be drawn under the usual ordinal complementarity assumptions on the objective function, assuming almost nothing about costs: the only requirement is that non-adjustment be costless. We use this insight to provide a general treatment of the le Chatelier principle based on adjustment costs. We extend these results to a fully dynamic, forward-looking model of adjustment over time: given only minimal structure on costs, optimal adjustment follows a monotone path. We apply our results to models of investment and of sticky prices.

Screening for breakthroughs with Gregorio Curello
[omitted proofs]  [60min video & slides]
AbstractWe identify a new dynamic agency problem: that of incentivising the prompt disclosure of productive information. To study it, we introduce a general model in which a technological breakthrough occurs at an uncertain time and is privately observed by an agent, and a principal must incentivise disclosure via her control of a payoff-relevant physical allocation. We uncover a deadline structure of optimal mechanisms: they have a simple deadline form in an important special case, and a graduated deadline structure in general. We apply our results to the design of unemployment insurance schemes.

Optimism, overconfidence, and moral hazard
[60min slides]
AbstractI revisit the standard moral-hazard model, in which an agent’s preference over contracts is rooted in costly effort choice. I characterise the behavioural content of the model in terms of empirically testable axioms, and show that the model’s parameters are identified. I propose general behavioural definitions of relative (over)confidence and optimism, and characterise these in terms of the parameters of the moral-hazard model. My formal results are rooted in a simple but powerful insight: that the moral-hazard model is closely related to the well-known ‘variational’ model of choice under uncertainty.

The preference lattice with Gregorio Curello
[60min slides]
AbstractMost comparisons of preferences are instances of single-crossing dominance. We examine the lattice structure of single-crossing dominance, proving characterisation, existence and uniqueness results for minimum upper bounds of arbitrary sets of preferences. We apply these theorems to derive new comparative statics theorems for collective choice and under analyst uncertainty, to characterise a general ‘maxmin’ class of uncertainty-averse preferences over Savage acts, and to revisit the tension between liberalism and Pareto-efficiency in social choice.

Statistical discrimination and statistical informativeness with Matteo Escudé, Paula Onuchic & Quitzé Valenzuela-Stookey
AbstractWe study the link between Phelps–Aigner–Cain-type statistical discrimination and familiar notions of statistical informativeness. Our central insight is that Blackwell’s Theorem, suitably relabeled, characterizes statistical discrimination in terms of statistical informativeness. This delivers one-half of Chambers and Echenique’s (2021) characterization of statistical discrimination as a corollary, and suggests a different interpretation of it: that discrimination is inevitable. In addition, Blackwell’s Theorem delivers a number of finer-grained insights into the nature of statistical discrimination. We argue that the discrimination-informativeness link is quite general, illustrating with an informativeness characterization of a different type of discrimination.