Aggregating Wrong Preferences

In a social choice setting, individuals may be unwilling to aggregate their preferences with what they regard as wrong preferences held by others because they lead to outcomes that harm themselves, harm others, are socially inefficient, or are morally unacceptable. People may still be willing to compromise with those who believe that although such preferences are wrong, society should nonetheless accept them. We offer two methods of two-level aggre- gation for such situations. In the first method, each member of society first aggregates the “corrected” individual preferences, and society then aggregates these aggregated views. In the second method, for each person, society first aggregates everyone’s views about that person’s preferences, and then aggregates the resulting individual “corrected” preferences. If these two methods yield the same social ranking, then the aggregation rule must be the sum of functions of the corrected utilities.