Skip to main content
Log in

Complementarity Enhanced Nash’s Mappings and Differentiable Homotopy Methods to Select Perfect Equilibria

  • Published:
Journal of Optimization Theory and Applications Aims and scope Submit manuscript

Abstract

To extend the concept of subgame perfect equilibrium to an extensive-form game with imperfect information but perfect recall, Selten (Int J Game Theory 4:25–55, 1975) formulated the notion of perfect equilibrium and attained its existence through the agent normal-form representation of the extensive-form game. As a strict refinement of Nash equilibrium, a perfect equilibrium always yields a sequential equilibrium. The selection of a perfect equilibrium thus plays an essential role in the applications of game theory. Moreover, a different procedure may select a different perfect equilibrium. The existence of Nash equilibrium was proved by Nash (Ann Math 54:289–295, 1951) through the construction of an elegant continuous mapping and an application of Brouwer’s fixed point theorem. This paper intends to enhance Nash’s mapping to select a perfect equilibrium. By incorporating the complementarity condition into the equilibrium system with Nash’s mapping through an artificial game, we successfully eliminate the nonnegativity constraints on a mixed strategy profile imposed by Nash’s mapping. In the artificial game, each player solves against a given mixed strategy profile a strictly convex quadratic optimization problem. This enhancement enables us to derive differentiable homotopy systems from Nash’s mapping and establish the existence of smooth paths for selecting a perfect equilibrium. The homotopy methods start from an arbitrary totally mixed strategy profile and numerically trace the smooth paths to a perfect equilibrium. Numerical results show that the methods are numerically stable and computationally efficient in search of a perfect equilibrium and outperform the existing differentiable homotopy method.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  1. Allgower, E.L., Georg, K.: Introduction to Numerical Continuation Methods, vol. 45. SIAM, Philadelphia (2003)

    Book  MATH  Google Scholar 

  2. Browder, F.E.: On continuity of fixed points under deformations of continuous mappings. Summa Bras. Math. 4, 183–191 (1960)

    MathSciNet  MATH  Google Scholar 

  3. Chen, Y., Dang, C.: A reformulation-based smooth path-following method for computing Nash equilibria. Econ. Theory Bull. 4, 231–246 (2016)

    Article  MathSciNet  Google Scholar 

  4. Chen, Y., Dang, C.: A reformulation-based simplicial homotopy method for approximating perfect equilibria. Comput. Econ. 54, 877–891 (2019)

    Article  Google Scholar 

  5. Chen, Y., Dang, C.: An extension of quantal response equilibrium and determination of perfect equilibrium. Games Econ. Behav. 124, 659–670 (2020)

    Article  MathSciNet  MATH  Google Scholar 

  6. Chen, Y., Dang, C.: A differentiable homotopy method to compute perfect equilibria. Math. Program. 185, 77–109 (2021)

    Article  MathSciNet  MATH  Google Scholar 

  7. Dang, C.: The \(D_{1}\)-triangulation of \(R^{n}\) for simplicial algorithms for computing solutions of nonlinear equations. Math. Oper. Res. 16, 148–161 (1991)

    Article  MathSciNet  Google Scholar 

  8. Dang, C.: Simplicial methods for approximating fixed point with applications in combinatorial optimizations. In: Pardalos, P., Du, D.-Z., Graham, R. (eds.) Handbook of Combinatorial Optimization, pp. 3015–3056. Springer, Boston (2013)

    Chapter  Google Scholar 

  9. Doup, T.M., Talman, A.J.J.: A continuous deformation algorithm on the product space of unit simplices. Math. Oper. Res. 12, 485–521 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  10. Eaves, B.C.: Homotopies for the computation of fixed points. Math. Program. 3, 1–22 (1972)

    Article  MathSciNet  MATH  Google Scholar 

  11. Facchinei, F., Pang, J.S.: Finite-Dimensional Variational Inequalities and Complementarity Problems. Springer, New York (2003)

    MATH  Google Scholar 

  12. Fiacco, A.V.: Introduction to Sensitivity and Stability Analysis in Nonlinear Programming. Academic Press, New York (1983)

    MATH  Google Scholar 

  13. Eaves, B.C., Schmedders, K.: General equilibrium models and homotopy methods. J. Econ. Dyn. Control 23, 1249–1279 (1999)

    Article  MathSciNet  MATH  Google Scholar 

  14. Govindan, S., Wilson, R.: A global Newton method to compute Nash equilibria. J. Econ. Theory 110, 65–86 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  15. Govindan, S., Wilson, R.: Computing Nash equilibria by iterated polymatrix approximation. J. Econ. Dyn. Control 28, 1229–1241 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  16. Govindan, S., Wilson, R.: A decomposition algorithm for n-player games. Econ. Theory 42, 97–117 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  17. Gutierrez, A.E., Mazorche, S.R., Herskovits, J., Chapiro, G.: An interior point algorithm for mixed complementarity nonlinear problems. J. Optim. Theory Appl. 175, 432–449 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  18. Haddou, M., Maheux, P.: Smoothing methods for nonlinear complementarity problems. J. Optim. Theory Appl. 160, 711–729 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  19. Harsanyi, J.C.: The tracing procedure: a Bayesian approach to defining a solution for \(n\)-person noncooperative games. Int. J. Game Theory 4, 61–94 (1975)

    Article  MathSciNet  MATH  Google Scholar 

  20. Harsanyi, J.C., Selten, R.: A General Theory of Equilibrium Selection in Games. MIT Press, Cambridge (1988)

    MATH  Google Scholar 

  21. Herings, P.J.J.: Two simple proofs of the feasibility of the linear tracing procedure. Econ. Theory 15, 485–490 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  22. Herings, P.J.J., van den Elzen, A.H.: Computation of the Nash equilibrium selected by the tracing procedure in n-person games. Games Econ. Behav. 38, 89–117 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  23. Herings, P.J.J., Peeters, R.J.A.P.: A differentiable homotopy method to compute Nash equilibria of \(n\)-person games. Econ. Theory 18, 159–185 (2001)

    Article  MATH  Google Scholar 

  24. Herings, P.J.J., Peeters, R.J.A.P.: Homotopy methods to compute equilibria in game theory. Econ. Theory 42, 119–156 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  25. Kreps, D.M., Wilson, R.: Sequential equilibria. Econometrica 50, 863–894 (1982)

    Article  MathSciNet  MATH  Google Scholar 

  26. Lei, M., He, Y.: An extragradient method for solving variational inequalities without monotonicity. J. Optim. Theory Appl. 188, 432–446 (2021)

    Article  MathSciNet  MATH  Google Scholar 

  27. Lemke, C.E., Howson, J.T., Jr.: Equilibrium points of bimatrix games. SIAM J. Appl. Math. 12, 413–423 (1964)

    Article  MathSciNet  MATH  Google Scholar 

  28. Myerson, R.B.: Refinements of the Nash equilibrium concept. Int. J. Game Theory 7, 73–80 (1978)

    Article  MathSciNet  MATH  Google Scholar 

  29. Myerson, R.B.: Game Theory: Analysis of Conflict. Harvard University Press, Cambridge (1991)

    MATH  Google Scholar 

  30. Nash, J.: Equilibrium point in n-person games. Proc. Natl. Acad. Sci. 36, 48–49 (1950)

    Article  MathSciNet  MATH  Google Scholar 

  31. Nash, J.: Noncooperative games. Ann. Math. 54, 289–295 (1951)

    Article  Google Scholar 

  32. Osborne, M.J., Rubinstein, A.: A Course in Game Theory. MIT Press, Cambridge (1994)

    MATH  Google Scholar 

  33. Pólik, I., Terlaky, T.: Interior point methods for nonlinear optimization. In: Di Pillo, G., Schoen, F. (eds.) Nonlinear Optimization, pp. 215–276. Springer, Berlin (2010)

    Chapter  MATH  Google Scholar 

  34. Rosenmüler, J.: On a generalization of the Lemke-Howson algorithm to noncooperative n-person games. SIAM J. Appl. Math. 21, 73–79 (1971)

    Article  MathSciNet  Google Scholar 

  35. Scarf, H.E.: The approximation of fixed points of a continuous mapping. SIAM J. Appl. Math. 15, 1328–1343 (1967)

    Article  MathSciNet  MATH  Google Scholar 

  36. Scarf, H.E., Hansen, T.: The Computation of Economic Equilibria. Yale University Press, New Haven (1973)

    Google Scholar 

  37. Selten, R.: Reexamination of the perfectness concept for equilibrium points in extensive games. Int. J. Game Theory 4, 25–55 (1975)

    Article  MathSciNet  MATH  Google Scholar 

  38. Todd, M.J.: The Computation of Fixed Points and Applications. Springer, Berlin (1976)

    Book  MATH  Google Scholar 

  39. van Damme, E.: Stability and Perfection of Nash Equilibria. Springer, Berlin (1991)

    Book  MATH  Google Scholar 

  40. van den Elzen, A.H., Talman, A.J.J.: An algorithmic approach towards the tracing procedure for bimatrix games. Games Econ. Behav. 28, 130–145 (1999)

    Article  MATH  Google Scholar 

  41. van der Laan, G., Talman, A.J.J.: A restart algorithm for computing fixed points without an extra dimension. Math. Program. 17, 74–84 (1979)

    Article  MathSciNet  MATH  Google Scholar 

  42. von Stengel, B., van den Elzen, A., Talman, D.: Computing normal form perfect equilibria for extensive two-person games. Econometrica 70, 693–715 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  43. Wilson, R.: Computing equilibria of n-person games. SIAM J. Appl. Math. 21, 80–87 (1971)

    Article  MathSciNet  MATH  Google Scholar 

  44. Zheng, H., Liu, L.: The sign-based methods for solving a class of nonlinear complementarity problems. J. Optim. Theory Appl. 180, 480–499 (2019)

    Article  MathSciNet  MATH  Google Scholar 

Download references

Acknowledgements

We are very grateful to the editor and two anonymous reviewers for their valuable comments and suggestions, which have significantly enhanced the quality of the paper. This work was partially supported by NSFC: 61976184.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Yiyin Cao.

Additional information

Communicated by Xinmin Yang.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Cao, Y., Dang, C. & Sun, Y. Complementarity Enhanced Nash’s Mappings and Differentiable Homotopy Methods to Select Perfect Equilibria. J Optim Theory Appl 192, 533–563 (2022). https://doi.org/10.1007/s10957-021-01977-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10957-021-01977-x

Keywords

Mathematics Subject Classification

Navigation