Preferenza sociale non transitiva e teorema di Arrow

Questo lavoro estende il teorema di impossiblità di Arrow al caso di preferenza sociale stretta non transitiva. In particolare, si dimostra che se una Funzione di Decisione Sociale (FDS) soddisfa le condizioni di dominio universale, indipendenza dalle alternative irrilevanti, transitività della relazione di indifferenza sociale, il principio di Pareto forte e la regola di indifferenza paretiana, allora la FDS deve essere dittatoriale. Vengono inoltre illustrate le implicazioni di tale risultato per il caso in cui la FDS soddisfa la condizione di dualità.

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Summary This paper extend's Arrow's impossiblity theorem to the case where strict social preference may be intransitive. The main result of the paper is that if a Social Decision Function satisfies Unrestricted Domain, Independence of Irrelevant Alternatives, Transitivity of Social Indifference, the Strong Pareto Principle, and the Pareto Indifference Rule, then there exists a dictator. An application of this result is a new impossibility theorem concerning SDF obeying the condition of Duality. As a by-product of this analysis, the relationships between Neutrality and Duality are somewhat clarified.

     

The demand-boost theory of exclusive dealing

This article unifies various approaches to the analysis of exclusive dealing that so far have been regarded as distinct. The common element of these approaches is that firms depart from efficient pricing, raising marginal prices above marginal costs. We show that with distorted prices, exclusive dealing can be directly profitable and anticompetitive provided that the dominant firm enjoys a competitive advantage over rivals. The dominant firm gains directly, rather than in the future, or in adjacent markets, thanks to the boost in demand it enjoys when buyers sign exclusive contracts. We discuss the implication of the theory for antitrust policy.     

Independence of irrelevant alternatives and consistency of choice

Summary. We show that Arrow's condition of independence of irrelevant alternatives is logically related to conditions of consistency of choice (in particular, to Arrow's choice axiom). The relation, however, is indirect. The link is provided by an independence condition due to Hansson (Synthese, 1969) which applies to fixed agenda social choice rules.     

Algorithmic Pricing What Implications for Competition Policy?

Review of Industrial Organization - Pricing decisions are increasingly in the “hands” of artificial algorithms. Scholars and competition authorities have voiced concerns that those...