The possibility of Arrovian social choice with the process of nomination

In this paper, we introduce an Arrovian social choice framework with the process of nomination. We consider a two-stage social choice procedure in which some alternatives are first nominated by aggregating the opinions of nominators, and then the society makes a collective choice from the nominated alternatives by aggregating the preferences of voters. Each nominator's opinion is a positive, negative, or neutral view as to whether each alternative deserves to be eligible for collective decision making. If a voter is a nominator, his preference space is restricted by his opinion as follows: he always prefers positive alternatives to neutral ones and neutral alternatives to negative ones, according to his opinion. When each nominating voter has such a preference space, we first characterize Arrow-consistent preference domains at the second stage of the social choice framework. Second, we find a resolution of Arrow's impossibility theorem when at least one nominating voter exists.