Plott's analysis reveals a subtlety. Non-welfare factors—physical characteristics of social states, people's motives in having the preferences they do, respect for rights, equality—none of these are to make any difference except indirectly, through their reflections in individual preferences.
Arrow's research has also explored the social choice theory, endogenous growth theorycollective decision making, the economics of information, and the economics of racial discrimination, among other topics.
Part three: There can be at most one dictator[ edit ] Part three: Since voter k is the dictator for B over C, the pivotal voter for B over C must appear among the first k voters. The name of this condition is misleading. It is sufficient that social preference is a complete and quasi-transitive relation, having a strict component that is transitive but an indifference component that, perhaps, is not transitive.
Facts Matter. Furthermore, by unanimity the societal outcome must rank B above C. See the entry on social choice theory for discussion of this important theme in contemporary theory of social choice. Making any or all of the indicated switches to the other ballots has no effect on the outcome. We call the voter whose ballot change causes this to happen the pivotal voter for B over A.