The cleaning up of waste present in transboundary rivers, which re- quires the cooperation of dierent authorities, is a problematic issue, espe- cially when responsibility for the discharge of the waste is not well-dened. Following Ni and Wang [12] we assume that a river is a segment divided...

We study axiomatically situations in which the society agrees to treat voters with different characteristics distinctly. In this setting, we propose a set of six intuitive axioms and show that they jointly characterize a new class of voting procedures, called Personalized Approval Voting....