46 research outputs found
False-Name Manipulation in Weighted Voting Games is Hard for Probabilistic Polynomial Time
False-name manipulation refers to the question of whether a player in a
weighted voting game can increase her power by splitting into several players
and distributing her weight among these false identities. Analogously to this
splitting problem, the beneficial merging problem asks whether a coalition of
players can increase their power in a weighted voting game by merging their
weights. Aziz et al. [ABEP11] analyze the problem of whether merging or
splitting players in weighted voting games is beneficial in terms of the
Shapley-Shubik and the normalized Banzhaf index, and so do Rey and Rothe [RR10]
for the probabilistic Banzhaf index. All these results provide merely
NP-hardness lower bounds for these problems, leaving the question about their
exact complexity open. For the Shapley--Shubik and the probabilistic Banzhaf
index, we raise these lower bounds to hardness for PP, "probabilistic
polynomial time", and provide matching upper bounds for beneficial merging and,
whenever the number of false identities is fixed, also for beneficial
splitting, thus resolving previous conjectures in the affirmative. It follows
from our results that beneficial merging and splitting for these two power
indices cannot be solved in NP, unless the polynomial hierarchy collapses,
which is considered highly unlikely
Behavioral Economics and the Public Sector
This thesis consists of four essays dealing with topics that are relevant for the public sector. The essays cover diverse issues of economics partly overlapping with political science. The topics reach from the taxation of labor over monetary policy to preferences over voting institutions. Throughout this thesis it is, in contrast to classical economics, not assumed that humans are necessarily fully rational. Once full rationality is no longer assumed, experiments become an important tool to learn about human behavior. Consequently, most of the work in this thesis makes use of economic experiments