Ever more kinked…

I have just revised oligopolies in theory of the firm (ToF) for HL students in IB2. I introduced the kinked demand curve a bit differently this time: I outlined the premises carefully, drew the market equilibrium point in a diagram and then asked the students to carefully obey the PED conditions of '...if I lower my price and the other firms follow...' in drawing the demand curve. This gave an entirely different outcome than most textbooks! I also played a game ...