We study mechanisms for selecting up to m out of n projects. Project managers' private information on quality is elicited through transfers. Under limited liability, the optimal mechanism selects projects that maximize some function of the project's observable and reported characteristics. When...

<Para ID="Par1">We provide several characterizations of unanimity decision rules, in a public choice model where preferences are constrained by attributes possessed by the alternatives (Nehring and Puppe, Games Econ Behavior 59:132–153, <CitationRef CitationID="CR27">2007a</CitationRef>; Nehring and Puppe, J Econ Theory 135:269–305, <CitationRef CitationID="CR28">2007b</CitationRef>). Solidarity...</citationref></citationref></para>

A collective decision problem is described by a set of agents, a profile of single-peaked preferences over the real line and a number of public facilities to be located. We consider public facilities that do not suffer from congestion and are non-excludable. We characterize the class of rules...