A two-part, 90-minute sequence designed for French Terminale Section Européenne (Maths in English) students, exploring probability models, expected value, decision trees, and game theory with a strong emphasis on oral communication.
To correct pronunciation: "Remember that we pronounce this as..."
To validate: "Your logic was very clear and easy to follow."
To challenge: "Is there a faster way to prove this strategy is safer?"
Speaking French during defense cycles will cost your group points! Slide 4 of 5
Class Debrief & Reflection
PLENARY REFLECTION
Q1
Risk vs. Expected Returns
Why does standard deviation act as a good mathematical measurement for "risk" in investment models? How does it differ from expected return?
Q2
The Logic of Monty Hall
Why does your gut tell you that switching doors shouldn't matter (50/50), when the formal mathematics proves that switching wins 2/3 of the time?
Excellent work in Session 1! Get ready for Game Theory in Session 2. Slide 5 of 5
SESSION 1
STATION 1: THE WARRANTY DILEMMA Topic: Expected Value
Part A (Distributions): Without warranty (\(X_1\)): \(P(X_1 = 4500) = 0.08\), \(P(X_1 = 0) = 0.92\).
With warranty (\(X_2\)): \(P(X_2 = 500) = 1.00\) (constant cost).
Part B (Expected value): \(E(X_1) = 4500 \times 0.08 + 0 \times 0.92 = \mathbf{360}\) euros.
\(E(X_2) = \mathbf{500}\) euros. Based purely on expected value, **self-insuring is optimal** since \(360 < 500\) (expected savings of €140).
STATION 2: THE STARTUP SYNDICATE Topic: Volatility & Risk Analysis
Part A (Distributions): Alpha (\(A\)): \(P(A=60000) = 0.20\), \(P(A=0) = 0.80\).
Beta (\(B\)): \(P(B=15000) = 0.60\), \(P(B=8000) = 0.40\).
Part B (Expectations & Volatility):
\(E(A) = 60000 \times 0.20 + 0 = \mathbf{12000}\) euros. Net expected profit: \(12000 - 10000 = \mathbf{2000}\) euros.
\(E(B) = 15000 \times 0.60 + 8000 \times 0.40 = 9000 + 3200 = \mathbf{12200}\) euros. Net expected profit: \(12200 - 10000 = \mathbf{2200}\) euros.
Startup Beta has both a **higher expected value** and **lower volatility (safer)** since its minimum outcome is €8,000 (Alpha's is €0).
STATION 3: CLINICAL DIAGNOSTICS Topic: Conditional Probability & Bayes
Part A (Tree probabilities): Top path: \(P(D) = 0.02\). Branch to \(T^+ = 0.95\), Branch to \(T^- = 0.05\).
Bottom path: \(P(\overline{D}) = 0.98\). Branch to \(T^+ = 0.10\) (1 - 0.90 specificity), Branch to \(T^- = 0.90\).
Part B (Posterior Probability calculation):
Total Positive test probability: \(P(T^+) = P(D \cap T^+) + P(\overline{D} \cap T^+) = (0.02 \times 0.95) + (0.98 \times 0.10) = 0.019 + 0.098 = 0.117\).
Apply Bayes' rule: \(P_{T^+}(D) = \frac{P(D \cap T^+)}{P(T^+)} = \frac{0.019}{0.117} \approx \mathbf{0.1624}\) (or **\(16.24\%\)**).
STATION 4: THE MONTY HALL SHOWDOWN Topic: Conditional Logic
Part A (Strategies): Initially, your chosen door (Door 1) has a \(1/3\) chance of having the car. The other two doors combined have a \(2/3\) chance.
Part B (Rigorous Proof): If you **Stay**: You only win if your initial choice was correct. Probability = \(\mathbf{1/3}\).
If you **Switch**: Since Monty always opens a door with a goat, switching wins if your initial choice was a goat (which forces Monty to open the *other* goat door, leaving the car behind the remaining closed door). Since the probability of choosing a goat initially is \(\mathbf{2/3}\), the probability of winning by switching is \(\mathbf{2/3}\).
The Decision Lab • Chances & Choices Guide Page 2 of 2
12, 12
0, 0
Beta
0, 0
8, 8
A Analyze Strategic Dominance
Do the players have dominant strategies in this game? Explain why or why not, citing the mathematical definitions.
B Find Multiple Nash Equilibria
How many pure Nash Equilibria exist in this game? Write down the strategy profile pairs and explain why they qualify.
Oral Challenge
English Speech Prompts
Practice defending coordination solutions aloud. Speak clearly and use these frames:
Phrases for Coordination
"The outcome depends entirely on..."
"Neither player has a dominant..."
"Both (Alpha, Alpha) and (Beta, Beta) are..."
Oral Question to Defend
"If both outcomes are equilibria, which one is 'better' for the market (Pareto dominant) and how do companies communicate to select it?"
The Strategist's Playbook • Station Packet
STATION 3: THE CLIMATE ACCORD
Focus: Public Goods, Free-Riding & Global Game Theory
Session 2
Unit: Game Theory Topic: Public Goods Target: Collective Action
The Free-Rider Dilemma
Two neighboring countries, Country A and Country B, are deciding on climate policies. They can either invest heavily to Reduce Emissions or choose to Do Nothing. Reducing emissions costs 6 units, but provides a clean atmosphere benefit of 5 units to BOTH countries.
Country B (Column Player)
Country A
Reduce
Do Nothing
Reduce
4, 4
-1, 5
Do Nothing
5, -1
0, 0
A The Math Behind the Numbers
Briefly verify why the payoffs in the matrix are correct. For example, explain why the profile (Reduce, Do Nothing) yields a payoff of -1 for Country A and 5 for Country B.
B The Global Equilibrium
Identify the Nash Equilibrium of this game. Explain the term "Free-Rider" using the strategies and payouts.
Oral Challenge
English Speech Prompts
Verbally defend ecological incentives in English. Work with these templates:
Environmental English
"The cost of reducing emissions is..."
"A country has an incentive to..."
"To free-ride on the other's effort..."
Oral Question to Defend
"How does game theory prove that voluntary agreements are highly likely to fail on carbon emissions? Suggest a mathematical mechanism to fix this."
The Strategist's Playbook • Station Packet
STATION 4: HAWK-DOVE CONFLICT
Focus: Anti-Coordination Games & Evolutionary Dynamics
Session 2
Unit: Game Theory Topic: Hawk-Dove Target: Anti-Coordination
To Fight or To Yield
Two firms are competing for a lucrative government contract worth 10 units. They can choose to be aggressive (Hawk strategy) or peaceful (Dove strategy). If both are Hawks, they fight, causing a loss of 8 units each (net payoff: \(5 - 8 = -3\)). If one is Hawk and one is Dove, the Hawk wins all.
Competitor Y (Column Player)
Competitor X
Hawk (Fight)
Dove (Share)
Hawk (Fight)
-3, -3
10, 0
Dove (Share)
0, 10
5, 5
A Find Pure Strategy Nash Equilibria
Identify the pure Nash Equilibria of this game. Explain why this is referred to as an "anti-coordination" game.
B Biological & Economic Analogy
Compare this game to the "game of chicken" or animal territory disputes. Write a brief reflection on how playing Hawk (or Dove) depends on what you believe the other will do.
Oral Challenge
English Speech Prompts
Verbally defend anti-coordination models aloud. Use the templates below:
Phrases for Anti-Coordination
"If I expect them to act aggressively, I..."
"The worst possible outcome is..."
"This anti-coordination equilibrium..."
Oral Question to Defend
"In animal fights, how does evolutionary biology prevent the lethal (Hawk, Hawk) outcome? Why do animals perform ritualized threats instead?"
Public Goods Game
STATION 4
Hawk-Dove
To fight aggressively or play passive. How does territorial conflict translate to corporate tenders and pricing models?
Anti-Coordination
Use the oral prompt cards at each station to defend your solutions aloud in English. Slide 4 of 5
Strategic Plenary: Oral Challenge
DEBATE & DISCUSS
D1
Solving the Free Rider Crisis
How can we rewrite the payoff matrices of the Climate Accord game so that the Nash Equilibrium changes from "Do Nothing" to "Reduce Emissions"? Explain the impact of carbon taxes or international fines.
D2
Biology vs. Business
Compare the Hawk-Dove game in biology to pricing wars in business. Is acting like a "Hawk" (aggressive low pricing to push others out) always a successful long-term strategy?
Congratulations! You have completed the Decision Lab sequence. Keep thinking strategically! Slide 5 of 5
STATION 2: TECH COORDINATION Type: Coordination Game
Part A (Dominant Strategies): Neither Company X nor Company Y has a dominant strategy. If X plays Alpha, Y wants to play Alpha (12 vs 0). If X plays Beta, Y wants to play Beta (8 vs 0). Optimal moves depend entirely on beliefs.
Part B (Nash Equilibria): Two pure Nash Equilibria exist: **(Alpha, Alpha)** with payoffs **(12, 12)** and **(Beta, Beta)** with payoffs **(8, 8)**. Both are stable, but (Alpha, Alpha) is Pareto-dominant since it yields higher utility for both players.
STATION 3: THE CLIMATE ACCORD (FREE RIDER) Type: Public Goods
Part A (Payoff Verification): Under (Reduce, Do Nothing), Country A pays 6 but both get 5. Thus, A gets \(5 - 6 = -1\) and B gets \(5 - 0 = 5\).
Part B (Free-Rider Equilibrium): Dominant strategy for both is **Do Nothing** (if other reduces: 5 vs 4; if other does nothing: 0 vs -1). Nash Equilibrium is **(Do Nothing, Do Nothing)** with payoffs **(0, 0)**. Country B "free-rides" when A reduces and B does nothing.
STATION 4: HAWK-DOVE CONFLICT Type: Anti-Coordination
Part A (Nash Equilibria): Two pure Nash Equilibria exist: **(Hawk, Dove)** with payoffs **(10, 0)** and **(Dove, Hawk)** with payoffs **(0, 10)**. It is "anti-coordination" because players want to choose different actions (one aggressive, one passive).
Part B (Analogy): If you believe the other will behave as a Hawk (fight), your best response is to play Dove (0 vs -3). If you believe they will play Dove, your best response is to play Hawk (10 vs 5). This explains territorial posturing.