This document discusses using game theory to analyze territorial planning issues. It presents a case study that used game theory to illuminate the transfer of Nantes Atlantique airport. It describes developing three games to model different interactions between players: an airport/airlines game, a regional airport game, and a "Community Game" between Nantes and Rennes. The Community Game modeled cooperation scenarios between the two communities. Experimental play of the Community Game provided results to help guide decision-making around airport cooperation. The document concludes that game theory and reflexive modeling can benefit territorial intelligence by clarifying player preferences and enabling simulations of actor interactions.

1. Game Theory and Territorial
Intelligence
Illustration from a Case Study
Michel Carrard
National School of Engineering, Bourges
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RESO-UMR 6590, Rennes 2 University

2. The objective of this contribution is to
present the principles of a
methodological work that has
mobilized game theory to illuminate
a town and country planning issue
(Carrard, 2009):
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3. PLAN
1 Context and Study Stakes
2 Methodology: Game Theory
3 The “Community Game”
4 Conclusion and Prospects
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4. Context and Study Stakes: the transfer of Nantes Atlantique airport
Aéroport NDDL
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http://www.aeroport-grandouest.fr

5. Context and Study Stakes: the main components of NDDL airport
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Dossier d’enquête préalable à la déclaration d’utilité publique, DGAC, 2006.

6. Context and Study Stakes: the impact of future NDDL airport
Western and northern
Britain: no impact Rennes: high impact
Nantes-Rennes: high
impact
Secondary urban
centers: high impact
Zone of influence of
NDDL airport: high NDDL airport: very high
impact impact
Nantes: very high
impact Rural area: low
impact
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Ernst&Young, CG d’Ille et Vilaine, 2006

7. Context and Study Stakes: problems
What status for future NDDL airport ?
Two options were discussed during the Public Debate (2003):
1) NDDL : « the largest airport in the West ? »
Resulting from competition between airports
or
2) NDDL : « the airport of the Great West ? »
Resulting from cooperation between airports
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8. PLAN
1 Context and Study Stakes
2 Methodology: Game Theory
3 The “Community Game”
4 Conclusion and Prospects
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9. Methodology: Reflexive Modelling
• Using game theory to analyze real situations
encounters two types of objection:
• 1) Game theory formalism is too restrictive to take the
complexity of reality into account.
• 2) Game theory does not “claim to say what is”, because
the assumptions of its models are too simplistic.
• Finally, the boundaries of game theory significantly
reduce its ability to help in decision making.
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10. Methodology: Reflexive Modelling
• Choosing a method: reflexive modelling (Thépot,
1998)
• “Reflexive modelling claims to act further upstream on the
mental representation by which the decision maker
structures his schematic vision of reality” (Thépot, 1998, p.
8 and following )
• Reflexive modelling sets itself the objective of extracting
from the real “a few stylized facts from which other stylized
facts are deduced by using simple models of game theory
which will be submitted to the discretion of the decision
maker” (Thépot, 1998).
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11. Methodology: game theory
“Reflexive modelling and normative modelling” in Thépot J., (dir.), 1998, Gestion et 11
théorie des jeux. L’interaction stratégique dans la décision, ed. Vuibert

12. Methodology: Reflexive Modelling
• Reflexive modelling creates space for game theory and
provides an objective as well as a methodology of
work:
• An objective since this type of modelling claims to help the
decision maker to clarify his strategic choices.
• A methodology as this approach only claims to describe the
nature of the strategic interactions of players so as to draw
logical implications and consequences.
• The aim is then less to determine the existence of
solutions than to clarify the nature of the difficulties to
reach them: coordination problems, conflicts of interest,
impasses in cooperation, reputation effects, etc....
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13. Methodology: Game Theory and
Prospective Approach
• Proximity can be found between the approach of
prospective scenario and the solution concept of game
theory.
• “A scenario is not the prospective reality but a means to represent it with
a view to illuminating the present action in the light of possible and
desirable futures” (Godet, 2004, p. 10)
• The solution concept refers to the conditions imposed on the strategies of
players, which if they are verified, become the solutions of the game
(Guerrien, 2002).
• The solution to a game, when it is reached, suggests the
existence of “a viable social order”, that is to say, such a
state of the world that the mutual interest of players ensures
its stability.
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14. Methodology: Game Theory and
Prospective Approach
• "Game theory can, on intuitive bases, ultimately identify some
socially possible futures among the many conceivable
scenarios” (Schmidt, 1999, p. 56).
• Three situations may come up which can help the futurist to
identify scenarios (Schmidt, 2000):
– The first, when the solution to a game is an empty set, then the
related scenario must be abandoned.
– The second, when the solution is unique, then the scenario
identified is the only stable state, and should be analyzed
carefully.
– Finally, a game may sometimes have several solutions. This can
lead the futurist to make recommendations based on criteria that
are external to the game itself.
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15. Methodology: Game Theory and
Prospective Approach
• "The intelligence of a social situation is scarcely reduced
to the understanding of a single game" (Schmidt, 2000, p.
258).
• In our study, we developed three games, which each in
their own way, have approached an aspect of the
interactions between the players concerned by the future
airport:
– The focus is on the institutional dimension of the players in
the “Community Game”
– In the other two games, the «Airport / Airlines Game» and
the « Airport in the Metropolitan Loire-Bretagne Area
game (EMLB)” attention is focused on airports and their
interactions with airlines.
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16. Methodology: Game Theory and
Prospective Approach
• This multiplication of games is the opportunity to
refine the analysis of certain types of interactions.
• Each game is an independent model but none is
completely cut off from the other two.
– the players are the same from one game to the other
– the solution to a game can affect the next game,
etc...
• All three games can be seen from a future oriented
approach, as a metagame (Howard, 1971, Schmidt,
2000) which includes such games as many sub-
games.
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17. PLAN
1 Context and Study Stakes
2 Methodology: Game Theory
3 The “Community Game”
4 Conclusion and Prospects
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18. The “Community Game”
A – Objective:
Reflecting on the conditions for cooperation between
Nantes and Rennes airports
Means used:
- Non-cooperative game for 2 players
- Solution concept used : Nash equilibrium and
Schapley value
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19. The “Community Game”
A – The players
A and B: two communities Objectives for A and B:
A has an airport leader Increasing access through their
(interregional calling) airports
B has a local airport (local Maximize their attractiveness
calling)
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20. The “community game”
A – the game
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21. The “Community Game”
A – Community Game Tree
A
Cooperation Competitive
B B
Cooperation Competitive Cooperation Competitive
Scenario 1 Scenario 2 Scenario 3 Scenario 4
Negotiated Challenged Hierarchical Competitive
Management Leadership Relationship Management
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22. The “Community Game”
A – Preference order
The payoff matrix for A
Assumption
(1 , X) (0 , X)
(3 , X) (2 , X)
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23. The “Community Game”
A – Preference order
The payoff matrix for B
Assumption
(X , 3) (X , 2)
(X , 0) (X , 1)
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24. The “Community Game”
A – The position of players with non-cooperative strategies
The payoff matrix
Assumption
(1 , 3) (0 , 2)
(3 , 0) (2 , 1)
Nash equilibrium
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25. Playing the “Community Game”
• In the context of reflexive modelling of the
situation, Rennes and Nantes players were offered
to participate in the “community game”
• This was, initially, to assess their preferences for
the scenarios from political, economic and social
criteria. Then, they were asked to play the game.
• As the proposal failed to reach its end, we will
present some results obtained with the test group
(8 participants).
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26. Playing the “Community Game”
B - Experimental game
Three decision criteria for A and B
1 - Political criterion Reelection of politicians
2 - Economic criterion The growth of GDP per capita
3 - Social criterion Employment (unemployment)
Assumption: Three criteria weigh the same (1 / 3) in the choice of strategies
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27. Playing the “Community Game”
B – Experimental game
1st rank 4th rank
(2,75 , 4,5) (-3 , 4,5) (0,25 , 4,75) (-3 , 3,25)
(5,25 , -1) (1 , -2) (4,25 , -3) (4,5 , 1)
Nash Equilibrium
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28. Playing the “Community Game”
B – Experimental game
1st rank 4th rank
(2,75 , 4,5) (-3 , 4,5) (0,25 , 4,75) (-3 , 3,25)
(5,25 , -1) (1 , -2) (4,25 , -3) (4,5 , 1)
Differential between rankings constitute margins from
which players can mutually adjust to (example 1) 28

29. Playing the “Community Game”
B – Experimental game
1st rank 4th rank
(2,75 , 4,5) (-3 , 4,5) (0,25 , 4,75) (-3 , 3,25)
(5,25 , -1) (1 , -2) (4,25 , -3) (4,5 , 1)
Differential between rankings constitute margins from
which players can mutually adjust to (example 2)
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30. PLAN
1 Context and Study Stakes
2 Methodology: Game Theory
3 The “Community Game”
4 Conclusion and Prospects
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31. Conclusion and Prospects
• If Game Theory concepts are not easily transferable to
real cases, Reflexive Modelling offers interesting
prospects to address situations in which the
interactions between actors are strong.
• Reflexive Modelling does not seek to determine an
optimal strategy for a decision maker but rather to
guide him in his decision making
• Reflexive Modelling requires a dialogue between the
decision maker (s) and the modeller.
• We also recalled that game theory allows a futurist
reading in so far as it allows to select the scenario
among a set of scenarios.
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32. Conclusion and Prospects
• Finally, with respect to the subject of this conference,
it appears that territorial intelligence can fully benefit
from the contributions of game theory.
• We will give two examples:
- The first, we have experienced in our study, relies on
game assessment by the players themselves with a view
to clarifying their preferences, beliefs, etc... (Reflexive
modelling).
- The second, is related to the development of evolutionary
games which, together with information technology tools,
allow simulations of cooperation and competition
between economic actors (Berro, Leroux, 2006).
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33. Thank you for your
attention
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