Browsing by Subject "Political sociology."

Now showing 1 - 4 of 4

Open Access
Explorations of self-selective social choice functions
(1999) Ünel, Bülent
In this study, we analyze self-selective social choice functions focusing on whether one can escape dictatoriality. Two ways are examined: In the first attempt, the set of social choice functions is restricted to tops only. With this restriction, selfselectivity turns out to be equivalent to dictatoriality. In the second, the set of prefence profiles restricted to single-peaked ones. Here we show that there are some self-selective social choice functions which are not dictatorial.
Open Access
Majority voting rule and oligarchic social choice rules
(2001) Pasin, Pelin
In the first part of this study majority voting rule for two alternatives and continuum agents is characterized. As in the finite agent case, symmetry among agents, neutrality between alternatives and positive responsiveness characterize majority voting rule. In the second part, the relation between T-monotonicity and the group which acts as the oligarchy in an oligarchic social choice rule, is analyzed. It is shown that the minimal coalition for which the social choice rule is monotonic constitutes the oligarchy.
Open Access
Party implementation
(2009) Apakan, Hasan Tahsin
In this study party implementation concept is introduced. Party implementation is an extension of classical implementation allowing different parties to have group-specific choice rules. Members of a party are assumed to act cooperatively according to a common preference. In this context, a choice rule is said to be party implementable if it is robust to co-operative manipulation. In this thesis some necessity and sufficiency results for party implementation are proven. In particular, it is shown that under some restrictions if the societies choice rule is party implementable, an alternative that is chosen by any group should also be chosen by the society. Conversely, it is shown that if the collective choice can be represented by the union of different groups’ choice, then the social choice rule should be party implementable.
Open Access
Two essays in social choice theory
(2000) Kaya, Ayça
Solution concepts which implement only monotonic social choice rules are characterized in terms of a new notion of monotonicity pertaining to solution concepts. For any given class G of mechanisms, it turns out that a solution concept a implements only monotonic social choice rules via mechanisms in G if and only if a is G-monotonic. Moreover, with each solution concept a, we associate a class G^ of mechanisms such that each a-implementable onto social choice function which takes on at least three different values is dictatorial if and only if a is Go-monotonic. Oligarchic social choice rules are characterized by the conjunction of unanimity and a monotonicity condition, oligarchic monotonicity, which is stronger than Maskin monotonicity. Given an oligarchic social choice rule, the coalition acting as the oligarchy turns out to be the minimal set T of agents such that the social choice mle is Maskin monotonic when the restriction of each profile to T is considered. Finally, the solution concepts which implement only oligarchic social choice rules are characterized in terms of oligarchic monotonicity modified for solution concepts.