This paper contributes to the ongoing methodological debate on context-free versus in-context presentation of experimental tasks. We report an experiment using the paradigm of a bribery experiment. In one condition, the task is presented in a typical bribery context, the other one uses abstract wording. Though the underlying context is heavily loaded with negative ethical preconceptions, we do ...

In this paper, we set up a framework to study approximation of manipulation, control, and bribery in elections. We show existence of approximation algorithms (even fully polynomial-time approximation schemes) as well as obtain inapproximability results. In particular, we show that a large subclass of scoring protocols admits fully polynomial-time approximation schemes for the coalitional weight...

This paper contributes to the ongoing methodological debate on context-free versus in-context presentation of experimental tasks. We report an experiment using the paradigm of a bribery experiment. In one condition, the task is presented in a typical bribery context, the other one uses abstract wording. Though the underlying context is heavily loaded with negative ethical preconceptions, we do ...

In many principal-agent relations, objective measures of the agents' performance are not available. In those cases, the principals have to rely on subjective performance measures for designing incentive schemes. Incentive schemes based on subjective performance measures open the possibilities for in uencing activities by the agents. This paper extends Lazear and Rosen's (1981) model of rank-ord...

We study the complexity of influencing elections through bribery: How computationally complex is it for an external actor to determine whether by a certain amount of bribing voters a specified candidate can be made the election’s winner? We study this problem for election systems as varied as scoring protocols and Dodgson voting, and in a variety of settings regarding homogeneous-vs.-nonhomogen...

We study the (parameterized) complexity of SHIFT BRIBERY for multiwinner voting rules. We focus on the SNTV, Bloc, k-Borda, and Chamberlin-Courant, as well as on approximate variants of the Chamberlin-Courant rule, since the original rule is NP-hard to compute. We show that SHIFT BRIBERY tends to be significantly harder in the multiwinner setting than in the single-winner one by showing setting...

We study the concept of bribery in the situation where voters are willing to change their votes as we ask them, but where their prices depend on the nature of the change we request. Our model is an extension of the one of Faliszewski et al. [9], where each voter has a single price for any change we may ask for. We show polynomial-time algorithms for our version of bribery for a broad range of v...

When faced with a regulatory constraint, firms can either comply, bribe the regulator to get around the rule, or lobby the government to relax it. We analyze this choice, and its consequences, in a simple dynamic model. In equilibrium, when the level of development is low, firms are more inclined to bend the rule through bribery but they tend to switch to lobbying when the level of development ...

Endriss et al. [1,2] initiated the complexity-theoretic study of problems related to judgment aggregation. We extend their results for manipulating two specific judgment aggregation procedures to a whole class of such procedures, and we obtain stronger results by considering not only the classical complexity (NP-hardness) but the parameterized complexity (W[2]-hardness) of these problems with r...