Resumen
There are many contexts in which it is necessary to choose a location for a public facility that is considered a public good by some agents, but a public bad for others. That is, each agent, who is located in one particular point, will have single-peaked preferences with the peak in her location (if she considers that the facility is a public good) or single-dipped preferences with the dip in her location (if she considers that the facility is a public bad). We show that in this domain we can escape from the Gibbard-Satterthwaite impossibility result and we characterize all rules that satisfy strategy-proofness and unanimity in this framework. Joint work with Marc Vorsatz (UNED & FEDEA)