Michal Lewandowski’s personal webpage

I conduct research on decision-making under risk, ambiguity, time delays, and strategic uncertainty. I am currently working as a PI in the OPUS research grant of the Polish National Science Center, measuring and characterizing attitudes toward uncertainty using indifference prices.

My research can be accesses via my Google Scholar, ResearchGate or ORCID profiles.

I am currenty working on several projects. Preliminary drafts are available below

Biseparable representations of the certainty equivalents

joint work with Jacek Chudziak

Abstract: We consider the following biseparable representation of the certainty equivalent: $F(x, y; p) = u^{−1}(w(p)u(x) + (1 − w(p))u(y))$, where $(x, y; p)$ is the binary monetary prospect, u is the utility function, and w is the probability weighting function. We provide a simple set of axioms characterizing this form for all binary prospects as well as for the subset of binary prospects, called simple prospects, in which one of the two payoffs is fixed. We consider both the case of general w and the case of expected utility, where w is the identity function. We discuss the extent to which such models can be identified, the issue of extending these models to a larger number of payoffs, and draw conclusions for model testing.

Preference imprecision or uncertainty aversion - decomposing WTA and WTP gap for uncertain prospects

joint work with Łukasz Woźny and Michał Jakubczyk

Abstract: We propose a setup to account for two leading explanations of the WTA-WTP disparity: one based on the loss aversion and the other based on preference imprecision. We propose two axioms that allows us to distinguish the part of WTA-WTP disparity atributed to each of these two explanations. Our approach is general and incorporates some of the leading models as special cases. To illustrate our approach we propose a simple experiment that allows to quantitatively decompose the WTA-WTP gap in the two analyzed channels.

Discounted Incremental Utility

joint work with Manel Baucells

Abstract: Most decisions involve multiple payoffs over time and under risk, as for instance the sequential play of a lottery. For an individual who cares not only about profit at the end, but also on how early these profits accrue, we apply a modified version of the axioms of subjective expected utility to obtain the Discounted Incremental Utility model.

Individual and collective rationality in carpooling

joint work with Pawel Kalczynki

Abstract: We define carpooling as a coalition game and present a socially optimal solution that minimizes the overall cost of commuting and is stable and fair. Instead of transferring costs between players, individual rationality is achieved by appropriate composition and assignment of drivers within carpools. We develop a three-step solution procedure, where our final solution is based on the stable pre-nucleolus of the underlying game. The results of computational experiments show that our procedure guarantees substantial gains from carpooling. These gains increase with the number of commuters and are comparable to gains achieved by centralized systems, which ignore stability and fairness.