We use the Shapley value and the nucleolus to analyze the impact of three controversial pipeline projects on the power structure in the Eurasian trade of natural gas. Two pipelines, `Nord Stream' and `South Stream', allow Russian gas to bypass transit countries, Ukraine and Belarus. The third...

This paper presents a formal theory of reciprocity. Reciprocity means that people reward kind actions and punish unkind ones. The theory takes into account that people evaluate the kindness of an action not only by its consequences but also by the intention underlying this action. The theory...

Everyone remembers a plot where a disadvantaged individual facing the prospect of failure, spends more effort, turns around the game and wins unexpectedly. Most tournament theories, however, predict the opposite pattern and see the disadvantaged agent investing less effort. We show that 'turn...