September 1999 <p> Roberts' "weak neutrality" or "weak welfarism" theorem concerns Sen social welfare functionals which are defined on an unrestricted domain of utility function profiles and satisfy independence of irrelevant alternatives, the Pareto condition, and a form of weak continuity....</p>

March 1997 <p> Arrow's ``impossibility'' and similar classical theorems are usually proved for an unrestricted domain of preference profiles. Recent work extends Arrow's theorem to various restricted but ``saturating'' domains of privately oriented, continuous, (strictly) convex, and (strictly)...</p>