Typically, three kinds of settings, under which decisions are made, are distinguished, certainty, uncertainty, and risk. In this view, uncertainty is defi ned narrowly, as a situation, in which the probability distribution is unknown. However, D. Ellsberg’s studies showed that ambiguity, defi ned as an intermediate condition between uncertainty and risk, could be considered as the fourth type of decision settings. Seen from this perspective, uncertainty is a more complex notion and it is commonly experienced with regard to important issues other than only total or partial lack of knowledge of probability. Following the review of concepts of uncertainty, we present examples of their impact on
everyday life economic decisions that are made in the domains of consumer behaviour, saving, investment, and entrepreneurship. Finally, we present some methods of coping with different kinds of uncertainty.

The article presents an important application of spatial generalization of Shapley value for simple games. Proposition presented by Shapley and Owen enables very interesting empirical interpretations. It has also strong contribution in the research of spatial voting models’ properties when there is no stable solution. This theorem enables us to fi nd the least unstable solution and therefore this is the valuable answer to the problem presented in the McKelvey’s theorem. The article presents the main postulates of the spatial voting theory, a geometric insight on which the general proof of Shapley-Owen theorem is based and empirical illustration of the presented concepts.

The aim of this paper is to analyse the relation between the structure of a school-group and the problem of bullying. Bullying is a specific type of school violence, that occurs when a perpetrator or a group of perpetrators repeatedly attack a relatively helpless victim. This type of violence involves not only bullies and their victims, but also bystanders - other students who witness the process of bullying. Bullies’ behavior is planned and aimed at building social status in the group, and the suffering of the victims is not their main goal. Bystanders play a major role in the process, as their approval or disapproval can either encourage or discourage the bully. Behaviour of bystanders is analysed, with the use of a modifi ed structurally embedded coordination game, in order to show how the structure of the group can infl uence the process of bullying.