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...

Minimum-cost spanning tree problems are well-known problems in the operations research literature. Some agents, located at different geographical places, want a service provided by a common supplier. Agents will be served through costly connections. Some part of the literature has focused,...