Endogenous Heterogeneity in Strategic Models: Symmetry-breaking via Strategic Substitutes and Nonconcavities



Consider a two-player normal form game Γ given by the tuple (X, Y, F, G).
Let X and Y be the action sets of player
1 and 2 respectively, such that X =
Y =[0,c] R. The maps F and G : X × Y R are the payoff functions of
players
1 and 2 respectively and F can be expressed as:

{U(x,y), x y

,    ,                                                 (1)

L(x, y),x < y

By symmetry of the game Γ, G can be expressed as:

{L(y, x), x y

,    ,                                                 (2)

U(y, x),x < y

Observe that, somewhat contrary to standard practice, the first argument of
F is the action of player
1 while the first argument of G is the action of player
2. It is useful to define the following sets:

U = {(x, y) R2 : x y} and L = {(x, y) R2 : x y}.

It will be assumed throughout the paper that U, L, F and G are jointly con-
tinuous functions of the two actions. Define the best response correspondences
(reaction curves) for players
1 and 2 respectively as r1 (y) = arg max{F (x, y):
x [0, c]} and r2 (x) = arg max{G(y, x):y [0, c]}.

As usual, a pure strategy Nash equilibrium (or PSNE for short), (x*,y*)
[0, c]2 is said to be symmetric if x* = y*, and asymmetric otherwise. It follows
from the symmetry of the game that if
(x*,y*) is a PSNE, (y*,x*) is also a
PSNE.

Each of the next three sections investigates a separate class of normal-form
symmetric games that always possess asymmetric Nash equilibria and no sym-
metric Nash equilibria. For each of the three classes, we provide a general result
establishing both the existence and the inexistence conclusions and an illustra-
tion based on previous studies where a special case of the result was derived in
a specific setting.

The definitions and main results from the theory of supermodular games
used in this paper are reviewed in the appendix in a very simple way, which is
sufficient for the purposes of this paper.



More intriguing information

1. Monopolistic Pricing in the Banking Industry: a Dynamic Model
2. The name is absent
3. Investment and Interest Rate Policy in the Open Economy
4. he Virtual Playground: an Educational Virtual Reality Environment for Evaluating Interactivity and Conceptual Learning
5. Target Acquisition in Multiscale Electronic Worlds
6. TWENTY-FIVE YEARS OF RESEARCH ON WOMEN FARMERS IN AFRICA: LESSONS AND IMPLICATIONS FOR AGRICULTURAL RESEARCH INSTITUTIONS; WITH AN ANNOTATED BIBLIOGRAPHY
7. The Environmental Kuznets Curve Under a New framework: Role of Social Capital in Water Pollution
8. Do Decision Makers' Debt-risk Attitudes Affect the Agency Costs of Debt?
9. For Whom is MAI? A theoretical Perspective on Multilateral Agreements on Investments
10. The name is absent