The paper contributes to the literature on other-regarding preferences challenging the narrow self-interest assumption. Experimental evidence confirms that the same individuals might express different otherregarding preferences in different situations or contexts. The structure of their interaction, their relative positions in it might trigger different behavioral patterns. In this paper we propose a model of multi-level other-regarding preferences assuming that different levels are actualized depending on the context in which an individual has to take her decision. We analyze the experimental trust game letting the players have multi-level preferences. Under certain parameterization and asymmetric information assumption, we show that the share given up by the leader of the game in favor of the follower is strictly monotonically increasing with altruism of the former. It is also demonstrated that utilitarian social welfare is increasing with the leader’s altruism if the players are not extremely risk-averse. In the case when information for both players is incomplete, a separating equilibrium exists allowing to distinguish between leaders with different other-regarding preferences.

Social choice theory is essentially about the constraints upon effective mechanisms for implementing desirable states of a society or a group, given the preferences and utilities of its members. Social choice theory is also, and much more generally, a conceptual examination of normative theories of society – theories that characterize what it is for state of affairs to be better from the social point of view. Social choice methods have different aims, for example democratic decision-making, epistemic decision-making, respecting individual rights of persons and groups, just distribution of goods. They are justified by the sets of postulates, which represent different basic social values.

The dynamic development of experimental economics, in particular of experimental work in game theory, has contributed to the questioning of the basic assumptions of classical game theory: the rationality and self-interest assumption. In response, those assumptions are being modified and more realistic models of human behavior in situations which can be described as games are being developed. The article provides a short overview of the models that abandon the self-interest assumption. An account is given mostly of the distributional models (i.a. inequity aversion models, model of quasi-maximin preferences). The results of the experiments designed to test the rival distributional models of social preferences are also presented in the article, as well as of the experiments that assess to the role played by intention-based reciprocity in motivating human behavior.

In 1970 A.K. Sen formulated the "Liberal Paradox" and he proved that there was a conflict between individual rights (Sen's "condition of liberalism") and social rationality (Pareto optimality). This article contains an analysis of classical conditions in the context of this inconsistency and a new way of approaching this problem. The datum for these considerations was a supposition that the conflict can appear only in societies composed of people with nonliberal preferences. The liberality level of preferences can be described as a position in a two-dimensional space. The first dimension is "interested in my own problems" and the other is "protection of other people's rights". The main result indicates when the conflict between liberalism and optimality appears. All analyses were based on full sets of individual preferences for two selected situations (the first one: 2 persons and 4 social alternatives and the other one: 2 persons with strong preferences and 6 social alternatives).

Analysis of vulnerability of selected social choice methods to strategic voting is presented in the article. Selected methods are: plurality voting, the Borda count and approval voting. Applied procedure allowed strategic voting of unlimited number of voters. With each method voters knew the outcome of the sincere voting, consistent with their real preferences. 24 variants differed on voting parameters; for each variant 1000 random profiles of preferences have been analyzed. Results are different from expected.

The article presents an analysis of the effects of the list apparentment institution introduced in the electoral rule for the sejmik of voivodship (regional council) and of some other changes which also had significant consequences. The effect analysis of these institutional solutions required primarily a comparison of specific political parties’ election results with the results these parties would have got under the „old” electoral rule, assuming no change in voters’ preferences resulting from the change in law. The electoral rule amendment had a significant impact on the results of specific parties, as measured by the number of mandates gained. Then, the authors investigated a number of alternative coalition strategies available to political parties, elaborating on the issue of effectiveness in actions undertaken by collective actors such as political parties. The authors proved that the results of the elections concerned depended on coalition strategies, rather than on election rules. Some players in the electoral game failed to achieve effectiveness in the attainment of the ultimate objective, i.e. to maximise the number of mandates gained, but the assessment of effectiveness provides different results if we assume that an important objective (though not equally important) was to maximise the results of the relevant bloc formed by apparentment. A matter of concern in the new electoral rule is the violation in 26% of constituencies of the monotonny criterion in the distribution of mandates resulting from the distribution of votes. In their concluding remarks, the authors put forward a proposal for a change in the electoral rule that better reflects the profiles of individual preferences in the social choice, while maintaining the apparentment institution.