Personal website
I am an Associate Professor in Economics at University of Sussex. I received my doctorate from University of Oxford. On this website you can find detailed information regarding my scientific research, personal interests, and materials intended for my students.
I thought if you lost the glasses you could fit right into one of those Guy Ritchie movies and be smoking cigarettes with Jason Statham.
One of my students’ first impression of me after seeing the picture above.
On pure altruism (with Łukasz Woźny)
Summary. We introduce a new approach to studying altruism by analyzing preference functions, which assign a decision-maker’s objectives to each individual they interact with, capturing how these objectives adjust in response to others’ preferences. Our key insight is that altruism aligns with the Pareto principle: when the preferences of the decision-maker and the affected individual agree, an altruistic decision-maker always chooses an option consistent with both. (This version: February 2026.)
Eliciting the just-noticeable difference
Summary. According to psychophysics, people are unable to discriminate between alternatives unless they are significantly different. I show how to elicit their preferences from their choices when this happens. This is the semiorder approach. (This version: December 2025. See also the Online appendix.)
Testing for production with complementarities (with John Quah)
Summary. How to tell if the production function at your firm exhibits production complementarities? We develop an axiomatic characterisation of this hypothesis. (This version: September 2014.)
The first draft of anything is shit.
Ernest Hemingway (1899-1961)
Complete and in chronological order.*
A revealed preference approach to approximate utility maximisation (2025): Journal of Economic Theory, 228.
Summary. Nobody believes in the model of utility maximisation, but we do believe that it is a good approximation of how consumers make their decisions. I provide a comprehensive method for eliciting preferences when the individuals are ‘almost’ utility maximising.
Revealed preference and revealed preference cycles: A survey (2024): Journal of Mathematical Economics, 113, with Josh Lanier and John Quah.
Summary. We discuss the importance of acyclicity conditions in the revealed preference literature. (Upon an invitation to the 50th anniversary issue of Journal of Mathematical Economics.)
Comparative statics with linear objectives: normal demand, monotone marginal costs, and ranking multi-prior beliefs (2024): Econometrica, 92 (1), pp 167-200, with John Quah.
Summary. Consider an optimisation problem with a linear objective. What is the necessary and sufficient condition under which the set of minimisers increases in a natural sense? We show that it is all about parallelograms. We apply our results to normal demand, monotone marginal costs, and comparative statics in models of ambiguity. Online supplement.
Revealed statistical consumer theory (2024): Economic Theory, 77, pp 823–847, with Roy Allen and John Rehbeck.
Summary. What if individuals care about a distribution of consumption, rather than consumption bundles? We characterise such a behaviour and show that it is equivalent to a model in which the consumer cares only about a statistic of the distribution.
Making sense of the monkey business: Re-examining tests of animal rationality (2022): Journal of Economic Behavior & Organization, 196, pp 220-228, with Roy Allen and John Rehbeck.
Summary. We discuss how to perform revealed preference tests on non-human animals. Spoiler: They do much better than human animals!
Markov distributional equilibrium dynamics in games with complementarities and no aggregate risk (2022): Theoretical Economics, 17, pp 725-762, with Łukasz Balbus, Kevin Reffett, and Łukasz Woźny.
Summary. Nine years in the making, but it’s finally here! If you want to know how to analyse and compute equilibrium transitional dynamics in games/economies with infinitely many agents and private shocks… search no more. This paper contains everything you need.
Just-noticeable difference as a behavioural foundation of the critical cost-efficiency index (2020): Journal of Economic Theory, 188.
Summary. Were you using Afriat’s efficiency index (CCEI) but didn’t know what was its behavioural interpretation? I show that it measures the inability to differentiate between alternatives. Now you know!
A qualitative theory of large games with strategic complementarities (2019): Economic Theory, 67, pp 497–523, with Łukasz Balbus, Kevin Reffett, and Łukasz Woźny.
Summary. We show how to compute equilibria and determine comparative statics in games with a continuum of players and strategic complementarities. Particularly useful when studying interactions in which payoffs of players are affected by the whole distribution of actions, rather than its aggregate.
Revealed time preference (2018): Games & Economic Behavior, 112, pp 67-77.
Summary. How to tell if someone is a discounted utility maximiser? I show how to do it when you observe a finite number of binary choices over delayed rewards. Spoiler: Often anything goes!
Efficiency of competitive equilibria in economies with time-dependent preferences (2015): Journal of Economic Theory, 159, pp 311-325.
Summary. In exchange economies where preferences of consumers change over time, competitive equilibria are efficient in a rather strong sense.
Differential information in large games with strategic complementarities (2015), Economic Theory, 59(1), pp 201-243, with Łukasz Balbus, Kevin Reffett, and Łukasz Woźny.
Summary. A follow up to the 2019 paper (although this one was published first). Now you can solve and determine comparative statics in games with a continuum of agents and strategic complementarities, when the information individuals have about the game varies.
* Not necessarily complete nor in chronological order.
All teaching materials are available on Canvas. Find the link below.
Wikipedia entry on Monotone comparative statics, prepared with John Quah.
Young man, in mathematics you don’t understand things. You just get used to them.
John von Neumann (1903-1957) in response to Felix T. Smith who had said: “I’m afraid I don’t understand the method of characteristics.”
I have been a member of the Department of Economics at University of Sussex since September 2018. I received my DPhil in Economics from University of Oxford. My research interests are focused on topics in monotone comparative statics and revealed preference analysis. However, I am also interested in, and have worked on, issues in theory of large games and general equilibrium. You can find my CV below.
I am interested the medieval history of Europe and the Middle East. In particular, I am fascinated with the relations between Byzantine Empire and Kingdoms of Outremer throughout the period of Crusades.
In my spare time, I play the guitar. I adore ragtime, Mississippi Delta blues, and a whole variety of rock-and-roll music that followed. My main inspirations are Son House and Chuck Berry, but I am also a great fan of Johnny Cash… and John Mayer… obviously.
As an academic I have the opportunity to travel a lot. I enjoy hiking (usually in cold and remote places). Photographs from my travels can be found on my social media. See the link below.
My guilty pleasures include: Dolly Parton, playing the ukulele, Star Trek, and dancing like Kevin Bacon in Footloose (the warehouse scene).
I’m smart enough to know that I’m dumb.
Richard Feynman (1918-1988)
