A polluted river network is populated with agents (e.g., firms, villages, municipalities, or countries) located upstream and downstream. This river network must be cleaned, the costs of which must be shared among the agents. We model this problem as a cost sharing problem on a tree network....

A river carries pollutants to people living along it if it is polluted. To make the water in the river clean, some costs are incurred. This poses a question of how to split the costs of cleaning the whole river among the agents located along it. To answer this question, we resort to the two main...

For a tolled highway where consecutive sections allow vehicles enter and exit unrestrictedly, we propose a simple toll pricing method. We show that the method is the unique method that satisfies the properties of Transit-proofness (No Merging or Splitting) and Cost Recovery. The...