For more than half a century experimental results accumulate that disprove prognostic value of perfect equilibrium, a concept derived from the principle of rationalistic egoism. The article is a short survey of popular experimental games in which actors make decisions of monetary consequences, thus shaping the income distribution in a group (dyad, in particular). A brief account is given of experimental research on ultimatum and dictator game, dictator's dilemma, trust game, centipede, gift exchange and public good game. Special focus is on dictator's dilemma which tests for readiness to benefit one's partner at one's own expense. This elementary personal dilemma turns out to constitute an essential part of more complicated and better known two- and multi-personal games.

Each of the EU enlargements raised problem of new apportionment of EP seats among EU member states. Each time solution was found in the process of multilateral negotiations, but since 1970s postulates to replace repeated negotiations by impartial mathematical formula have been raised, based on some concept of ”degressive proportionality”. When in 2007 EP started works on new apportionment before 2009 elections, one of the proposed solutions was ”parabolic method” of V. Ramirez, but in October 2007 EP again accepted allotment of seats not based on a mathematical formula, on the ground that ”apportionment is a political issue and can not be solved only on the mathematical base”. The paper presents the new proposal of degressively proportional apportionment method ua. The ua method leaves to the politicians decision about strength of the degressiveness of proportionality, but after this is politically accepted, the apportionment is based only on an of impartial mathematical formula.

This paper is an introduction to a relatively new (and little known in Poland) field of economic research – the experimental economics. We briefly sketch its history and main research areas, and describe some of most important findings in laboratory experiments and their significance for the mainstream economics. We also present a sample of the experiments conducted in the experimental economics seminar at Warsaw University.