Papers (by Topic)

1) Stability of Cooperation in the Prisoner’s Dilemma

•  Instability of defection in the prisoner’s dilemma under best experienced payoff dynamics (pre-print SSRN, download), Journal of Economic Theory, 197, 105174, 2021. Joint with: Srinivas Arigapudi and Igal Milchtaich.
  Idea: We show that plausible dynamics in which each new agent bases her play on testing each action a few times globally convergence to a state in which the frequency of cooperation is slightly below 50%.

•  Observations on Cooperation, Review of Economic Studies, 85(4), 2253-2282, 2018 (SSRN pre-print, download, supplementary material, presentation). Joint with Erik Mohlin.
  Idea: Can cooperation be sustained in interactions between strangers, when each agent observes a few past actions played by his partner against other opponents?

•  Three steps ahead, Theoretical Economics, 10, 203-241, 2015 (screen-view pdf).
  Idea: I present an evolutionary foundation for limited foresight, in which the agents have different foresight capacities, and everyone looks at most three steps ahead.

2) Learning Dynamics in Games

•  Heterogeneous Noise and Stable Miscoordination (download, presentation, short presentation). Joint with Srinivas Arigapudi & Amnon Schreiber.
  Idea: A key result in evolutionary game theory is that populations playing coordination games always converge to pure coordinated outcomes. By contrast, we show that plausible learning dynamics, in which some (but not all) of new agents rely on anecdotal evidence might induce stable mixed state with miscoordination.

• Mentors and Recombinators: Multi-Dimensional Social Learning (GDrive download). Joint with Srinivas Arigapudi, Omer Edhan, Ziv Hellman.
  Idea: We study learning dynamics in which new agents learn how to play by combining traits from various successful incumbents.

• Stable Mixing in Hawk–Dove Games under Best Experienced Payoff Dynamics (GDrive download). Joint with Srinivas Arigapudi.
  Idea: Plausible dynamics, in which agents occasionally revise their actions based on the payoffs obtained in a few past interactions, can yield convergence to inefficient interior stationary states in hawk-dove games. 

• Social Learning and the Shadow of the Past, Journal of Economic Theory, 177, 426-460, 2018 (SSRN pre-print, download). Joint with Erik Mohlin.
  Idea: Under what circumstances the initial behavior of the population has a lasting effect on social learning processes?

• The Endowment Effect as Blessing, International Economic Review, 59(3), 1159-1186, 2018 (SSRN pre-print, download). Joint with Roee Teper and Sivan Frenkel.
  Idea: Cognitive biases that approximately compensate for each other may co-evolve together. We demonstrate it by studying the endowment effect and the winner's curse.·     

3) Evolutionary Foundation of Seemingly Irrational Behavior

·    Naive analytics equilibrium (download, short presentation (pdf), long presentation, video-recorded presentation). Joint with Ron Berman.
Idea: Naive data analytics that results in imprecise measurement of advertising and pricing response increases firm profits due to the indirect (strategic) impact of competition.

·    The Benefits of Coarse Preferences (download), working paper. Joint with Joe Halpern & Eyal Winter.
Idea: We study the strategic advantages of coarsening one’s utility by clustering nearby payoffs together.

·    Promises and Endogenous Reneging Costs (Pre-print: SSRN, download, on-line appendix, Mathematica code, presentation), Journal of Economic Theory, 187, 105024, 2020.Joint with David Sturrock.
Idea: Evolutionary forces may lead agents into internalizing an intermediate level of cost when breaking promises.

·    Biased-Belief Equilibrium (pre-print SSRN, download, presentation), American Economic Journal: Microeconomics, 12(2), 1-40, 2020. Joint with Eyal Winter.
Idea: We study a novel solution concept in which (1) each player chooses a best-response strategy to his distorted belief about the opponent’s strategy, and (2) the distortion functions form best responses to one another.

·    Rule rationality, International Economic Review, 57(3), 997-1026, 2016 (SSRN pre-print, download). Joint with Eyal Winter.
Idea: We study "rules of thumbs" that bundle together several games, in environments in which such rules can be observed by the opponent.

·    Justifiable choice (SSRN pre-print, download), Games and Economic Behavior, 76(2), 375-390, 2012.
Idea: Axiomatic model of incomplete preferences, in which an agent has several utility functions, and he chooses elements that maximize at least one of these utilities. (related note: tradeoff contrast effect in choices between lotteries).

4) Evolutionary Foundation of Risk Attitude

•  Evolutionary Foundation for Heterogeneity in Risk Aversion (pre-print SSRN, download, slides,simulation code). Journal of Economic Theory, 105617, 2023. Joint with Ilan Nehama.
  Idea: We argue that natural selection had endowed people with (1) risk-averse preferences, (2) heterogeneity in the level of risk aversion, and (3) the optimal distribution can be approximated by constant relative risk aversion utilities with relative risk aversion between zero and two.

•  Evolution, heritable risk, and skewness loving (screen-view version, presentation, supplemental simulation code: pdf, Python), Theoretical Economics, 16, 403–424, 2021. Joint with Arthur Robson.
  Idea: Nature induces agents to prefer heritable risk over both aggregate risk and idiosyncratic risk, and to be skewness loving.

• Overconfidence and diversification, (SSRN pre-print, download), American Economic Journal: Microeconomics, 6(1), 134-153, 2014 (online appendix).
  Idea: Explaining why risk-averse principals may prefer overconfident agents in various strategic interactions, and demonstrating how overconfidence may have evolved due to the gene's interest in risk diversification.

5) Evolutionary Game Theory: Methodology and Solution Concepts

• Coevolution of Deception and Preferences: Darwin and Nash Meet Machiavelli (pre-print SSRN, download, supplementary analysis, presentation), Games and Economic Behavior, 113, 223-247, 2019. Joint with Erik Mohlin.
  Idea: We study how deception and preferences might co-evolve together.

• Instability of Belief-free Equilibria, Journal of Economic Theory, 168, 261-286, 2017 (SSRN pre-print, download).
  Idea: The "belief-free" equilibria, which are often used in the literature on repeated games with private monitoring, are "extremely" unstable.

• Language, meaning, and games: A model of communication, coordination, and evolution: Comment, (SSRN pre-print, download), American Economic Review, 104(6), 1857-63, 2014.
  Idea: Demichelis and Weibull (2008) show that adding lexicographic lying costs to coordination games with cheap talk yields a sharp prediction: only the efficient outcome is evolutionary stable. I show that this result is caused only by the discontinuity of preferences, and that such discontinuity is not an appealing assumption in evolutionary models.

• Stability and trembles in extensive-form games, Games and Economic Behavior, 84, 132-136, 2014 (SSRN pre-print, download).
  Idea: Selten's (1983) notion of "Limit ESS" is "wrong" in its assumption that "mutants" are more rare than "trembling" incumbents.

6) Games with Private Information

• Social welfare in search games with asymmetric information (pre-print SSRN, download, presentation). Joint with Gilad Bavly and Amnon Schreiber. Journal of Economic Theory, 202, 105462, 2022.
  Idea: We study the maximal social payoff in equilibria of games in which players search for a hidden prize, where they have asymmetric information about the prize’s location.

•  Communication, Renegotiation, and Coordination with Private Values (pre-print SSRN, download, presentation, video-recorded presentation). Joint with Christoph Kuzmics. Games and Economic Behavior, 143, 51-76, 2024.
  Idea: We characterize the essentially unique renegotiation-proof equilibrium in coordination game with private idiosyncratic preferences, which induce novel simple behavior.

• Social Media and Democracy (download). Joint with Ronen Gradwohl and Arye Hillman.
  Idea: We apply Bayesian persuasion tools to study the power of a social media designer to manipulate election outcomes.

 7) Experimental Economics

• Comparing the Effects of Non-Monetary Incentives and Monetary Incentives on Prosocial Behavior (download), European Econmic Review, 165, 104740, 2024. Joint with Yamit Asulin & Nira Munichor.
  Idea: We test in a field experiment the impact of various incentives on the efforts and productivity of youth volunteers (small monetary incentives, moderate monetary incentives, and non-monetary incentives).

• Strategies in the infinitely repeated prisoner's dilemma: A cluster analysis (download,  GitHub data and code). Joint with  Itay Tubul.
  Idea: We apply a new technique of cluster analysis to study which strategies are used in experiments of the infinitely repeated prisoner's dilemma.

• Social image, observer identity, and crowding up (GDrive download). Joint with Yamit Asulin, Nira Munichor & Ro’i Zultan.
  Idea: We do a field experiment to test the impact of monetary incentives and observation of effort by either a friend or a random student in the school's cohort, on the efforts of volunteering students

• Experimental observations on cooperation. Work in progress. Joint with Erik Mohlin & Matthew Embrey. Work in progress.
  Idea: The experiments will test the key predictions of Heller & Mohlin (2018) regarding the behavior in the prisoner's dilemma with random matching, where each agent can observe the opponent's behavior in a couple of past interactions.

8) Financial Risks and Risk Indices

• Short-Term Investments and Indices of Risk (screen-view version, pre-print, Theoretical Economics, 15(3), 891–921, 2020. Joint with Amnon Schreiber.
  Idea: In various short-term investment decisions regarding assets with continuous returns, all agents rank all gambles in the same way, and these rankings are represented by the same risk indices as in the case of CARA utility and normal risky assets.

• Banks’ Risk-Taking and Creditors’ Bargaining Power (pre-print SSRN, download), Journal of Corporate Finance, 74, 102198, 2022. Joint with Sharon Peleg-Lazar and Alon Raviv.
  Idea: We study how the bank's level of risk taking is determined by a bargaining process between the bank's shareholders and the subdebt holders.

•  A Closed-Form Solution to the Risk-Taking Motivation of Subordinated Debtholders (SSRN pre-print, download), Economics Letters, 181, 169-173, 2019. Joint with Sharon Peleg-Lazar and Alon Raviv.
  Idea: We clarify and extend Black and Cox's (1976) analysis of the value of the junior debt of a firm, and discuss implications regarding the ability of subdebt holders to monitor bank risk. 

9) Communication and Correlation in Games

• Communication, correlation and cheap-talk in games with public information (SSRN pre-print, download), Games and Economic Behavior, 74(1), 222-234, 2012. Joint with Eilon Solan and Tristan Tomala.
  Idea: We study how communication equilibrium payoffs can be obtained by unmediated cheap-talk procedures.

• Sequential correlated equilibrium in stopping games (SSRN pre-print, download) Operations Research, 60(1), 209-224, 2012 (related note: comment on distribution equilibrium).
  Idea: I present and prove existence of a new solution concept for an interesting family of infinite-horizon dynamic games.

• Minority-proof cheap-talk protocol, (SSRN pre-print, download) Games and Economic Behavior, 69 (2), 394-400, 2010 (extended version).
  Idea: Direct pre-play communication allow to implement correlated equilibria in a way that is resistant to deviations of fewer than half the players.

• All-stage strong correlated equilibrium, (SSRN pre-print, download), Games and Economic Behavior, 69 (1), 184-188, 2010.
  Idea: I study a solution concept in setups where players get correlated recommendations how to play at several stages.