The Complexity of Power-Index Comparison
| dc.creator | Faliszewski, Piotr | |
| dc.creator | Hemaspaandra, Lane A. | |
| dc.date | 2008-01-30 | |
| dc.date.accessioned | 2026-07-07T08:57:15Z | |
| dc.date.available | 2026-07-07T08:57:15Z | |
| dc.description | We study the complexity of the following problem: Given two weighted voting games G' and G'' that each contain a player p, in which of these games is p's power index value higher? We study this problem with respect to both the Shapley-Shubik power index [SS54] and the Banzhaf power index [Ban65,DS79]. Our main result is that for both of these power indices the problem is complete for probabilistic polynomial time (i.e., is PP-complete). We apply our results to partially resolve some recently proposed problems regarding the complexity of weighted voting games. We also study the complexity of the raw Shapley-Shubik power index. Deng and Papadimitriou [DP94] showed that the raw Shapley-Shubik power index is #P-metric-complete. We strengthen this by showing that the raw Shapley-Shubik power index is many-one complete for #P. And our strengthening cannot possibly be further improved to parsimonious completeness, since we observe that, in contrast with the raw Banzhaf power index, the raw Shapley-Shubik power index is not #P-parsimonious-complete. | |
| dc.description | 12 pages | |
| dc.identifier | https://arxiv.org/abs/0801.4585 | |
| dc.identifier | http://arxiv.org/abs/0801.4585 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/146894 | |
| dc.subject | Computational Complexity | |
| dc.subject | Computer Science and Game Theory | |
| dc.subject | I.2.11; F.2.2; F.1.3 | |
| dc.title | The Complexity of Power-Index Comparison | |
| dc.type | text |