A Game-Theoretic Rationale for Vagueness

• Published in: Linguistics and philosophy 2003-10, Vol.26 (5), p.637-659
• Main Author: de Jaegher, Kris
• Format: Article
• Language: English
• Subjects: Axioms; Conflicts of interest; Coordinate systems; Game theory; Honesty; Linguistic ambiguity; Linguistics; Maxims; Nash equilibrium; Philosophy of language. Logic; Political elections; Signals
• ISSN: 0165-0157; 1573-0549
• DOI: 10.1023/A:1025853728992

Although game-theoretic rationales for strategic generality & strategic ambiguity in communication with conflict of interest have been demonstrated by V. P. Crawford & J. Sobel (1982) & by E. Aragones & Z. Neeman (2000), respectively, the phenomenon of vagueness in communication games is less straightforward, as strategic vagueness requires that the concept of Nash equilibrium be replaced by that of correlated equilibrium & nonstrategic vagueness is currently controversial. Accordingly, D. Lewis's philosophy of language, based on game theory, is adapted to new developments in game theory & extended to include the concept of correlated equilibrium, thereby providing the basis of a rationale for vagueness in a game context: by choosing a form of self-expression that is more vague than necessary, a player ensures that communication can continue in the presence of conflict. This approach relies on approximate common knowledge instead of full common knowledge & is linked to T. Williamson's (1994) epistemic view of vagueness; the proposed rationale for vagueness is elaborated in an application to a signaling game. 6 Figures, 22 References. J. Hitchcock