Andy


Andriy (Andy) Zapechelnyuk
School of Economics
University of Edinburgh
31 Buccleuch Place
Edinburgh EH8 9JT
United Kingdom
Location: 31 Buccleuch Place, Room 4.01
Email: Andy.Zapechelnyuk (ατ) ed.ac.uk
Phone: Microsoft Teams
I am a Professor of Economics at the University of Edinburgh. I got a PhD from Stony Brook University in 2005. Before landing at Edinburgh in 2022, I spent some time as a researcher at the Center for the Study of Rationality (Hebrew University of Jerusalem) and the Hausdorff Center for Mathematics (University of Bonn), and I have taught at Kyiv School of Economics, Queen Mary University of London, University of Glasgow, and University of St Andrews.
My research interests lie in the field of microeconomic theory and applications, focusing on communication and information design, optimal contracts, and robust decision theory.
Working Papers
‣ Sequential obfuscation and toxic argumentation
We study an information design problem where two competing senders move sequentially. The second mover can either reveal more information (constructive argumentation) or obfuscate the first mover's information (toxic argumentation). We show that sequential obfuscation of an initially disclosed state never reveals more, and sometimes reveals strictly less information than sequential disclosure of an initially hidden state. Sequential obfuscation is completely uninformative when the senders are risk averse or risk neutral, or when they have zero-sum preferences. By contrast, sequential disclosure generally reveals some information, and it is fully revealing when the senders are risk neutral or have zero-sum preferences.
‣ On the equivalence of information design by uninformed and informed principals
We compare information design, or Bayesian persuasion, by uninformed and informed principals. We show that, under the assumptions of monotone preferences of the principal and nondegenerate information structures, a Pareto undominated outcome is implementable by the uninformed principal if and only if it is implementable by the informed principal.
‣ A model of debates: Moderation vs free speech (with Tymofiy Mylovanov)
This paper provides a framework to study communication conflicts, such as political debates, using a novel model of competition in Bayesian persuasion. Debating parties can "frame" their arguments for maximal impact. They also can "spam" the discussion to distract the audience from the opponent's arguments. We find that spamming is more detrimental to truth discovery than framing. When parties are allowed to speak freely, spamming can kill truth discovery and make communication uninformative. By contrast, framing is disciplined by competition. If the conflict between parties is strong and the number of arguments is restricted, the parties reveal the truth.
‣ Compromise, don't optimize: Generalizing perfect Bayesian equilibrium to allow for ambiguity (with Karl Schlag)
[previously titled "Compromise, don't optimize: A prior-free alternative to perfect Bayesian equilibrium"]
We introduce a solution concept for extensive-form games of incomplete information in which players are allowed to entertain multiple beliefs about what they do not know in the game. Players make dynamically consistent choices by looking for compromises that yield a good performance under each of their beliefs, anticipating their future choices. Our solution concept is called perfect compromise equilibrium. It generalizes perfect Bayesian equilibrium. We show how it deals with ambiguity in Cournot and Bertrand markets, public good provision, Spence's job market signaling, bilateral trade with common value, and forecasting.
‣ Persuasion under insufficient reason (with Anton Kolotilin) [Slides]
A sender designs how to disclose information about the state of the world to persuade a receiver to accept a proposal. The sender is ignorant about both the receiver's type and his risk attitude. The sender applies the principle of maximum entropy to resolve her ignorance. We show that the maximum-entropy utility is risk neutral if nothing is known about the agent's utility, and it is CARA if the average utility is known. Furthermore, the optimal signal is either fully revealing or completely uninformative if nothing is known about the distribution of the agent's type, or if its mean is known; the optimal signal is a censorship if the mean and variance are known. To derive our results, we propose a novel representation of preference over lotteries.
‣ Bargaining and trade without using priors (with Karl Schlag)
We study bargaining under incomplete information, with applications to trade and to provision of public good. In our setting, agents not only agree on how they share their output, but also on how much output they produce. We are interested in bargaining rules that do not depend on priors. We find a unique rule that satisfies a set of axioms. Under this rule, the higher the surplus, the more output is produced. Moreover, the produced output is shared as in the Nash bargaining solution. We present a dynamic protocol that implements this rule for any priors. Heterogeneous discount factors and degrees of risk aversion can be included.
‣ Are there "Ratatouille" restaurants? On anticorrelation of food quality and hygiene (with Hisayuki Yoshimoto)
We study the empirical relationship between hygiene conditions in restaurants and their food quality rated by both professional reviewers and consumers. Using evidence from the UK, we show that this relationship is negative and statistically significant. So, a higher food quality rating is generally associated with a less sanitary kitchen. We find that 3% of Michelin starred restaurants in our dataset have poor hygiene conditions, while the same is true for only 2% of non-Michelin starred restaurants. Our findings illuminate potential channels through which the anticorrelation between food quality and hygiene effort could be mitigated, and can be helpful for hygiene inspectors to prioritize restaurants in their inspection schedule.
‣ Persuasion meets delegation (with Anton Kolotilin)
A principal can restrict an agent's information (the persuasion problem) or restrict an agent's discretion (the delegation problem). We show that these problems are generally equivalent — solving one solves the other. We use tools from the persuasion literature to generalize and extend many results in the delegation literature, as well as to address novel delegation problems, such as monopoly regulation with a participation constraint.
‣ Value of information when searching for a secretary (with Karl Schlag)
The secretary problem is the canonical model of search under ambiguity, in which secretaries are being interviewed in a random order. We assume that the number of secretaries is unknown and that one cares for the value of the secretary. We measure the value of information as a multiplier that describes how much better off one could have been had one known the distribution of secretaries' values. It is evaluated in the worst case, for all distributions and at all rounds of search. Under perfect recall, knowledge of the applicant pool size and their distribution can improve one's payoff at most 4 times. Knowledge that the values are i.i.d. does not improve one's payoff.
‣ Competing e-commerce intermediaries (with Alexander Matros)
We consider a model where two e-commerce platforms, such as internet auctions, compete for sellers who are heterogeneous in their time preferences. Contrary to the literature which argues that if two platforms coexist in equilibrium, then the “law of one price” must hold, we demonstrate that two platforms may set different prices and have positive equilibrium profits by exploiting heterogeneity of sellers' time preferences. In such an equilibrium less patient sellers choose the more popular, but more expensive, platform, while more patient sellers prefer the less popular and cheaper one.
Publications
‣ Censorship as optimal persuasion
(with Anton Kolotilin and Tymofiy Mylovanov)
Theoretical Economics 17 (2022), 561-585 [Open Access]
(with Karl Schlag)
Theoretical Economics 16 (2021), 1431-1470 [Open Access]
[an earlier working paper version is here]
‣ Bayesian persuasion and information design: Perspectives and open issues
Introduction to the Special Issue on Communication and Persuasion
(with Emir Kamenica and Kyungmin Kim)
Economic Theory 72 (2021), 701-704 [doi]
‣ Optimal quality certification
American Economic Review: Insights 2 (2020), 161-176 [doi]
‣ Job search costs and incentives
(with Ro'i Zultan)
Economic Theory Bulletin 8 (2020), 181-202 [doi]
‣ Persuasion of a privately informed receiver
(with Anton Kolotilin, Tymofiy Mylovanov, and Ming Li)
Econometrica 85 (2017), 1949-1964 [doi]
‣ Optimal allocation with ex-post verification and limited penalties
(with Tymofiy Mylovanov)
American Economic Review 107 (2017), 2666-2694 [doi] [Online Appendix]
[earlier versions titled "Optimality of non-competitive allocation rules" and "Value of competition in allocation and search problems"]
(with Karl Schlag)
Journal of Economic Theory 169 (2017), 145-169 [doi]
[an earlier version titled “Decision making in environments without priors”]
‣ An axiomatization of multiple-choice test scoring
Economics Letters 132 (2015), 24-27 [doi]
‣ Eliciting information from a committee
Journal of Economic Theory 148 (2013), 2049-2067 [doi]
(with Tymofiy Mylovanov)
International Economic Review 54 (2013), 769-785 [doi]
‣ No-regret dynamics and fictitious play
(with Yannick Viossat)
Journal of Economic Theory 148 (2013), 825-842 [doi]
‣ Decision rules revealing commonly known events
(with Tymofiy Mylovanov)
Economics Letters 119 (2013), 8-10 [doi]
‣ On the impossibility of achieving no regrets in repeated games
(with Karl Schlag)
Journal of Economic Behavior and Organization 81 (2012), 153-158 [doi]
‣ Optimal mechanisms for an auction mediator
(with Alexander Matros)
International Journal of Industrial Organization 29 (2011), 426-431 [doi]
‣ Bargaining with a property rights owner
(with Yair Tauman)
Games and Economic Behavior 70 (2010), 132-145 [doi]
‣ On (non-) monotonicity of cooperative solutions
(with Yair Tauman)
International Journal of Game Theory 39 (2010), 171-175 [doi]
‣ Better-reply dynamics with bounded recall
Mathematics of Operations Research 33 (2008), 869-879 [doi]
‣ Optimal fees in internet auctions
(with Alexander Matros)
Review of Economic Design 12 (2008), 155-163 [doi]
‣ Strategic complements and substitutes, and potential games
(with Pradeep Dubey and Ori Haimanko)
Games and Economic Behavior 54 (2006), 77-94 [doi]
Grants and Sponsored Events
‣ Project: Theoretical Foundations and Design of Persuasion Mechanisms (2017–2020)
Funded by Economic and Social Research Council (United Kingdom)
Research Team:
- Andy Zapechelnyuk (University of St Andrews)
- Hisayuki Yoshimoto (University of Glasgow)
- Anton Kolotilin (UNSW Sydney)
‣ Event: An online Inaugral Lecture on "Economics of Persuasion and Strategic Information Manipulation" (2021)
Organized by the University of St Andrews
‣ Event: Seminar Series on Communication and Persuasion (2020)
Sponsored by Economic and Social Research Council (United Kingdom)
Co-organisers:
- Kyungmin Kim (Emory University)
- Andy Zapechelnyuk (University of St Andrews)
‣ Event: Workshop on Political Economy, Adam Smith Business School, University of Glasgow (2015)
Sponsored by Scottish Institute for Research in Economics (United Kingdom)
Co-organisers:
- Herve Moulin (University of Glasgow)
- Andy Zapechelnyuk (University of St Andrews)
‣ Project: Agent-based Simulation of the Wholesale Electricity Market of Ukraine (2007–2009)
Funded by International Development Research Centre (Canada)
Research Team:
- Andy Zapechelnyuk (University of St Andrews)
- Valeriy Tsaplin (National Energy and Utilities Regulatory Commission, Ukraine)
- Iryna Sikora (Ricardo Energy & Environment)
Teaching
EC3302 Game Theory
‣ Textbook: P. K. Dutta "Strategies and Games"
EC5220 Game Theory
‣ Textbook: M. Maschler, E. Solan, and S. Zamir "Game Theory"