On Single-peaked Domains and Min-max Rules

We consider social choice problems where different agents can have different sets of admissible single-peaked preferences. We show every unanimous and strategy-proof social choice function on such domains satisfies Pareto property and tops-onlyness. Further, we characterize all domains on which (i) every unanimous and strategy-proof social choice function is a min-max rule, and (ii) every min-max rule is strategy-proof. As an application of our result, we obtain a characterization of the unanimous and strategy-proof social choice functions on maximal single-peaked domains (Moulin (1980), Weymark (2011)), minimally rich single-peaked domains (Peters et al. (2014)), maximal regular single-crossing domains (Saporiti (2009), Saporiti (2014)), and distance based single-peaked domains.