Template-Type: ReDIF-Paper 1.0
Title: Convex Choice
Author-Name: Narvin Kartik
Author-Email: nkartik@gmail.com
Author-Name: Andreas Kleiner
Author-Email: andykleiner@gmail.com
Classification-JEL: D82
Keywords: single crossing; incentive compatibility; mechanism design; cheap talk

Abstract: 
For multidimensional Euclidean type spaces, we study convex choice: from any choice set, the set of types that make the same choice is convex. We establish
that, in a suitable sense, this property characterizes the sufficiency of local incentive constraints. Convex choice is also of interest more broadly, e.g., in cheaptalk
games. We tie convex choice to a notion of directional single-crossing differences (DSCD). For an expected-utility agent choosing among lotteries, DSCD
implies that preferences are either one-dimensional or must take the affine form that has been tractable in multidimensional mechanism design.


Note: 
Length: 39
Creation-Date: 2025-03
Revision-Date:
File-URL: https://www.crctr224.de/research/discussion-papers/archive/dp676
File-Format: application/pdf
Handle: RePEc:bon:boncrc:CRCTR224_2025_676