Generalized median voter (GMV) rules on the single-peaked preference domain are group strategy-proof. We show that if incomplete information coexists with the ability to commit to coalitional agreements, then GMV rules can be susceptible to insincere voting by groups with heterogeneous beliefs. We identify strategic compromise as a novel source of insincere voting in this environment. Our two main results characterize the set of fair, efficient, and robust voting rules: those that ensure sincere voting under asymmetric information and coalition formation. Each result uses a different notion of robustness, and both give (at most) two alternatives special treatment, with the remaining alternatives chosen according to a type of consensus. JEL Classifications: C71, C78, D70, D80

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