Template-Type: ReDIF-Paper 1.0
Title: The Dimensions of Consensus
Author-Name: Benny Moldovanu
Author-Email: mold@uni-bonn.de
Author-Name: Alex Gershkov
Author-Email: alexg@huji.ac.il
Author-Name: Xianwen Shi
Author-Email: xianwen.shi@utoronto.ca
Classification-JEL: D82, D71
Keywords: multi-dimensional  voting , welfare , bundling

Abstract: We study a multi-dimensional collective decision under incomplete information. Agents have Euclidean preferences and vote by simple majority on each issue (dimension), 
yielding the coordinate-wise median. Judicious rotations of the orthogonal axes - the issues that are voted upon - lead to welfare improvements. If the agents' types are drawn 
from a distribution with independent marginals then, under weak conditions, voting on the original issues is not optimal. If, in addition, the marginals are identical, then voting 
first on the total sum and next on the differences is often welfare superior to voting on the original issues. We also provide various lower bounds on incentive efficiency: in particular, 
if agents' types are drawn from a log-concave density with symmetric marginals, a second-best voting mechanism attains at least 88% of the first-best efficiency.
Note: 
Length: 47
Creation-Date: 2018-07
Revision-Date: 
File-URL: https://www.crctr224.de/research/discussion-papers/archive/dp029
File-Format: application/pdf
Handle: RePEc:bon:boncrc:CRCTR224_2018_029