in the gounod and bertrand models, competing players are on an equal footing in the market and thus their behaviour is similar. moreover, their decisions are simultaneous. when firm a is making a decision, it is not aware of firm b's decision. in fact, however, in some markets the positions of competing players are not symmetrical, and the asymmetry in market positions gives rise to an asymmetry in the order of decisions. usually, small firms observe the behaviour of large firms before deciding on their own responses. the model developed by the german economist starkelberg reflects this asymmetrical competition.