PWORLD: A Precedent-Based Global Simulation

Abstract

A "world model" is constructed where precedent searching is one of the primary driving mechanisms. The simulation assumes that nations in the system are utility maximizers but that they have relatively primitive decision mechanisms and are strongly influenced by their previous short-term successes and those of other states in the system. This model of foreign-policy decision making has been heavily influenced by recent artificial intelligence studies and simulations.

States in the simulation can follow one of three distinct strategies to maximize growth: imperialism, militarism, or trade. In each of these modes, a state can either increase or decrease its level of behavior, or it can switch modes. Decisions to switch are based on the success of the policy in increasing simulated GNP relative to earlier projections of how much GNP would increase. If a policy is clearly not working, a nation implements the reverse of it, if the policy is not producing major improvements, the nation randomly experiments or looks at the success of other nations in the system and follows whatever has worked for them. If a policy is clearly successful, it is continued.

The simulation was run using a system vaguely characteristic of the 19th-century world system, with 5 large, 5 medium, and 10 small nations. The resulting behavior is generally plausible, with bounded and fairly diverse activity depending on the random experimentation involved Because of the weak bounded rationality, the system does not lock on to a single pattern of behavior based on initial conditions, and so, for example, situations exist where medium powers eventually become stronger than the initial major powers. The most common pattern is one of a combination of trade links and imperialism, with about half the minor power being colonized and some exchange of colonies occurring through conflict. Keywords: artificial intelligence, foreign policy, global simulation, precedent-searching simulation, world modeling, simulation.

Get full access to this article

View all access options for this article.

References

Alker, Hayward J. , & Christensen, C. (1972). From causal modeling to artificial intelligence : The evolving of a U.N. peace-making simulation. In J. A. Laponce & Paul Smoker (Eds.), Experimentation and simulation m political science (pp. 174-224). Toronto: University of Toronto Press.

Alker, Hayward J. , & Greenberg, W. (1976). On simulating collective security regime alternatives . In M. Bonham & M. Shapiro (Eds.), Thought and action m foreign policy (pp. 263-306). Basel: Birkhauser-Verlag .

Anderson, Paul A. (1981). Justifications and precedents as constraints in foreign policy decision-making. American Journal of Political Science, 25, 738-761.

Bonham, G. Matthew , & Shapiro, Michael J. (1976). Explanation of the unexpected: The Syrian intervention in Jordan in 1970. In Robert Axelrod (Ed.), The structure of decision (pp. 113-141). Princeton: Princeton University Press.

Bremer, Stuart A. (1977) Simulated worlds. Princeton : Princeton University Press.

Brito, D.L. , & Intriligator, Michael D. (1973). Some applications of the maximum principle to the problem of an armaments race. Modeling and Simulation, 4, 140-144.

Brito, D.L. , & Intriligator, Michael D. (1974). Uncertainty and the stability of the armaments race. Annals of Economic and Social Measurement, 3, 279-292.

Brito, D.L. , & Intriligator, Michael D. (1982). Arms races: Behavioral and economic dimensions. In Judith Gillespie & Dina A. Zinnes (Eds.), Missing elements m political inquiry Logic and levels of analysis (pp. 314-341). Beverly Hills, CA: Sage.

Bueno de Mesquita, Bruce. (1981). The war trap. New Haven: Yale University Press.

10.

Carbonell, Jaime G. (1983). Learning by analogy: Formulating and generalizing plans from past experience. In Ryszaid S. Michalski , J. G. Carbonell , & Tom M. Mitchell (Eds.), Machine learning An artificial intelligence approach (pp. 137-161). Palo Alto, CA: Tioga Publishing.

11.

George, Alexander L. (1979). Case studies and theory development: The method of structured, focused comparison. In Paul G. Lauren (Ed.), Diplomacy: New approaches in history, theory and policy (pp. 43-68). New York: Free Press .

12.

Gillespie, John V. , Zinnes, Dina A. , & Tahim, G.S. (1975). Foreign military assistance and the armaments race. A differential game model with control. Peace Research Society International Papers, 25, 35-51.

13.

Gillespie, John V. , Zinnes, Dina A. , & Tahim, G.S. (1978). Transforming a nation-dominant international system . Journal of Conflict Resolution, 22, 547-564.

14.

Gillespie, John V. , Zinnes, Dina A. , Tahim, G.S. , Schrodt, Philip A. , & Rubison, R.M. (1977). An optimal control model of arms races. American Political Science Review, 71, 226-244.

15.

Hughes, Barry B. (1985). World models: The bases of difference. International Studies Quarterly, 29, 77-101.

16.

Intriligator, Michael D. , & Brito, D.L. (1985). Can arms races lead to the outbreak of war? Journal of Conflict Resolution, 28, 63-84.

17.

Leavitt, Michael. (1971). A computer simulation of international alliance behavior. Dissertation, Northwestern University.

18.

Mefford, Dwain. (1984, March). Formulating foreign policy on the basis of historical analogies: An application of developments in artificial intelligence . Paper presented at the International Studies Association, Atlanta.

19.

Morgenthau, Hans J. (1973). Politics among nations (5th ed.). New York: Knopf.

20.

Newell, Allan , & Simon, Herbert. (1972). Human problem solving . Englewood Cliffs, NJ: Prentice-Hall .

21.

Russett, Bruce , & Starr, Harvey. (1984). World politics. San Francisco: Freeman.

22.

Samuelson, Paul. (1980). Economics (11 th ed.). New York: McGraw-Hill.

23.

Schrodt, Philip A. (1984, August). Artificial intelligence and international crisis: An application of pattern recognition. Paper presented at the American Political Science Association, Washington, DC.

24.

Schrodt, Philip A. (1985). Precedent-based logic and rational choice: A comparison . In Michael Don Ward & Urs Luterbacher (Eds. Dynamic models of international conflict (pp. 373-400). Boulder, co: Lynn Reinner Publishing.

25.

Schrodt, Philip A. (1986a, August). PWORLD: A precedent-based global simulation . Paper presented at the American Political Science Association, Washington, DC.

26.

Schrodt, Philip A. (1986b, April). Set prediction using a Holland classifier . Paper presented at the International Studies Association, Anaheim, CA.

27.

Schrodt, Philip A. (1987a, April). Classification of international conflict outcomes using a bootstrapped CLS algorithm. Paper presented at the International Studies Association, Washington, DC.

28.

Schrodt, Philip A. (1987b). Event sequences, pattern recognition and foreign policy decision-making. In Stephen Cimbala (Ed.), Artificial intelligence and national security (pp. 89-108). Lexington, MA. Lexington Books.

29.

Simon, Herbert. (1979). Models of thought. New Haven : Yale University Press.

30.

Simon, Herbert (1982). The sciences of the artificial (2d ed.). Cambridge, MA Massachusetts Institute of Technology Press.

31.

Simon, Herbert. (1985). Human nature in politics The dialogue of psychology with political science. American Pohtical Science Review, 79, 293-304.

32.

Tanaka, Akihiko. (1984). China, China watching and CHINA_WATCHER. In Donald A. Sylvan & Steve Chan (Eds.), Foreign policy decision making. Perception, cognition and artificial intelligence (pp. 310-344). New York: Praeger.

33.

Ward, Michael Don (Ed.). (1985). Theories, models and simulation in international relations. Boulder, CO. Westview

34.

Winston, Patrick Henry. (1984). Artificial intelligence (2d ed.). Reading, MA: Addison-Wesley .

35.

Zinnes, Dina A. , Van Houwelling, Douglas , & Van Atta, Richard. (1969). A test of some properties of the balance of power theory in a computer simulation. Unpublished manuscript, Indiana University.