Loss aversion or preference imprecision? What drives the WTA-WTP disparity?, 2026
(joint with Michal Lewandowski and Michal Jakubczyk)

We propose a framework that, while eliminating the endowment effect, accounts for the two leading explanations of the disparity between willingness to accept (WTA) and willingness to pay (WTP): loss aversion and preference imprecision. Our approach applies to incomplete preferences under both risk and ambiguity. We introduce axioms that characterize the disparity and each of its two components. We show that the WTA-WTP disparity is a monetary measure (i.e., a premium) of uncertainty aversion, with hedging, rather than risk, serving as the neutrality benchmark. We derive comparative statics results for this measure with respect to both individuals and prospects. Our framework is general and encompasses several models, including multiple-utility multiple-prior models, as special cases.

In a related paper Loss aversion or preference imprecision? What drives the WTA-WTP disparity? An experimental illustration we report results of an experiment decomposing the disparity between willingness- to-pay (WTA) and willingness-to-pay (WTP) into two leading motives: loss aversion and preference imprecision. First, the WTA–WTP gap is positive for the vast majority of subjects. Second, preference imprecision accounts for a substantial share of the gap, ranging from 34% to 59%. Third, subjects cluster into three broad groups according to the primary driver of the WTA–WTP gap: (i) no preference imprecision, with the entire gap driven by sure or strong UA; (ii) a combination of sure or strong UA and preference imprecision; and (iii) predominantly preference imprecision. Many subjects in the third group exhibit negative sure UA (capturing sure uncertainty loving), yet display a positive overall UA due to substantial preference imprecision. Finally, we also replicate recent findings of no correlation between WTA and WTP and, in addition, documents a positive correlation between the WTA–WTP gap (=uncertainty aversion), and our measure of loss aversion (=sure uncertainty aversion).

Interim correlated rationalizability in large games, 2025
(joint with Lukasz Balbus, Michael Greinecker and Kevin Reffett)

We provide general theoretical foundations for modeling strategic uncertainty in large distributional Bayesian games with general type spaces, using a version of interim correlated rationalizability. We then focus on the case in which payoff functions are supermodular in actions, as is common in the literature on global games. This structure allows us to identify extremal interim correlated rationalizable solutions with extremal interim Bayes–Nash equilibria. Notably, no order structure on types is assumed. We illustrate our framework and results using the large versions of the electronic mail game and a global game.

Balancedness and Lindahl equilibrium, 2025
(joint with Sayantan Ghosal)

Condorcet winners, though they do not guarantee unanimity, are often a focal point for public policy. Can Lindahl prices and transfers, which ensure unanimity, be used to finance these policies? In settings where preferences are characterized by bliss points, we propose a condition, called balancedness, which requires that a policy lie in the interior of the convex hull of agents’ bliss points. We show that any such policy (and not just Condorcet winners) can be decentralized as a Lindahl equilibrium. Our results provide first and second welfare theorems for Lindahl equilibria with satiated preferences.

Iterative monotone comparative statics, 2023
(joint with Lukasz Balbus and Wojciech Olszewski and Kevin Reffett)

We propose a novel approach to equilibrium comparative statics in economic environments where complementarities play a critical role, including environments in which the existing methods for obtaining monotone comparative statics appear inadequate. Our approach is dynamic and, methodologically, in the spirit of the celebrated ''correspondence principle'', a concept first presented in the work of Samuelson (1947). It applies even to: (a) environments with a continuum of equilibria (b) environments in which all equilibria are unstable; and (c) chaotic environments, in which adaptive learning sequences may not converge. Finally, our propositions extend several previously existing results.

Dynastic preferences, recursive utility and time consistency, 2023
(joint with Lukasz Balbus and Kevin Reffett)

We consider a class of infinite horizon, stochastic, non-stationary dynastic consumption-savings models with a general forms of recursive, time-varying altruistic preferences including direct and indirect pure altruism as well as paternalistic altruism. It is well-known such models lead to time-inconsistent dynastic preferences. Within this class of economies, we propose a novel set-iterative procedure for characterizing all Markov perfect time-consistent solutions in the space of increasing investments. Our approach involves both: value functions and policy iterations. We prove existence of Markov Perfect equilibria in stationary, periodic and also non-stationary strategies. We provide numerous applications to altruistic growth models, behavioral discounting models and collective household models and also discuss the role of various certainty equivalence operators.

On collective intertemporal choice, time-consistent decision rules and altruism, 2021 (joint with Lukasz Balbus and Jean-Pierre Drugeon)

We consider a dynamic decision problem of a collective-household with heterogeneous discount factors. We prove existence a time-consistent decision rule in Markovian policies. In fact, decision rules we consider are characterized by monotone and Lipschitz continuous investments policies. We provide sufficient conditions for the validity of the (generalized) first-order approach. Finally, we propose a novel method to approximate the constructed decision rule by a sequence of equilibria of bequest games with paternalistic altruism.

Efficiency in rewarding academic journal publications. The case of Poland, 2021 (joint with Wojciech Charemza and Michal Lewandowski)

We consider the efficiency of a mechanism for incentivising publication in academic journals where a research supervisory body awards points for papers that appear in quality publications. Building on the principal-agent literature with hidden types, we assume that such a body wants to maximise the expected prestige of academic disciplines. It sets up a reward system so that researchers who are aiming to maximise their own rewards also maximise the objective function of the research supervisory body, through their submission decisions. The model is calibrated to the reward scheme introduced within the Polish higher education reform in 2018, for which a series of policy recommendations is given.

Repeated moral hazard with costly self-control, 2017

In this paper I solve for the optimal dynamic contract when an agent exhibits costly self control, demonstrating that reduction of agent’s temptations can provide incentives. Intrinsic motivation is most powerful when temptations are high. Then, the moral hazard problem can be mitigated. The optimal contract calls for a lower bonus deferral than for agents with no temptations. Under limited commitment, presence of self-control also reduces agent’s willingness to break or renegotiate the contract, and can make the optimal contract spot implementable. Impact of self-control on the cost of implementation as well as on willingness to save is ambiguous.

An experiment on temptation and attitude towards paternalism, 2017
(joint with Michal Krawczyk)

In this project we investigate experimentally the link between self-control and attitude towards paternalism in the context of food choice. We invite our subjects for a free lunch: a beef burger or a turkey. We verify in a pre-test that the beef burger is considered (much) more tasty and tempting, while the turkey is seen as healthier. In the experiment proper, we observe what menus subjects assign to one another – i.e. whether they let them choose or paternalistically assign the healthy option. We also record how they react to such choices made for them by another subject. Finally, we give them an opportunity to restrict future choices for themselves (a commitment device useful in case of self-control problems). There is a strong link between these three tendencies, suggesting a common thread underlying the use of commitment devices and paternalistic behavior as well as approval thereof in environments involving temptations. We discuss policy implications of our findings.

Some others

Lecture notes on Microeconomics, ISBN: 978-83-65416-11-7, Agencja Reklamowa TOP, 2016 [pdf].

Wodzeni na ekonomiczne pokuszenie, Obserwator finansowy, 2015 [link].

Niespójnosc czasowa decyzji, czyli o zeglowaniu, przestawianiu budzika i rzucaniu palenia
[wspólautor M. Jakubczyk], Gazeta SGH, nr 252, [pdf].

Wynagrodzenia polskich menedzerów: wysokie, ale malo motywujace
[wspólautor: A. Kunysz], Harward Business Review, nr 63, 2008, [Link].

Komplementarnosc dóbr i zachowan w ekonomii
[wspólautor M. Jakubczyk, M. Knauff], Gazeta SGH, nr 226, 2006, [pdf].

Drazliwy temat
[wspólautor K. Latuszynski], Personel i Zarzadzanie, nr 5 (194), 2006, [pdf].