Suchergebnisse

Arrow's Impossibility Theorem and Sen's Minimal Liberalism example impose 'impossibility' roadblocks on progress. A reinterpretation explained in this article exposes what causes these negative conclusions, which permits the development of positive resolutions that retain the spirit of Arrow's and Sen's assumptions. What precipitates difficulties is surprisingly common, and it affects most disciplines. This insight identifies how to analyze other puzzles such as conflicting laws or controversies over voting rules. An unexpected bonus is that this social science issue defines a research agenda to address the 'dark matter' mystery confronting astronomers.

Riker (Liberalism against populism, Waveland, New York, 1982) famously argued that Arrow's impossibility theorem undermined the logical foundations of "populism", the view that in a democracy, laws and policies ought to express "the will of the people". In response, his critics have questioned the use of Arrow's theorem on the grounds that not all configurations of preferences are likely to occur in practice; the critics allege, in particular, that majority preference cycles, whose possibility the theorem exploits, rarely happen. In this essay, I argue that the critics' rejoinder to Riker misses the mark even if its factual claim about preferences is correct: Arrow's theorem and related results threaten the populist's principle of democratic legitimacy even if majority preference cycles never occur. In this particular context, the assumption of an unrestricted domain is justified irrespective of the preferences citizens are likely to have.

Abstract
Arrow (1950) famously showed the impossibility of aggregating individual preference orders into a social preference order (together with basic desiderata). This paper shows that it is possible to aggregate individual choice functions, that satisfy almost any condition weaker than WARP, into a social choice function that satisfy the same condition (and also Arrow's desiderata).