It is certainly true that imitation is everywhere, from sport to business, from dancing to dressing, from driving to singing. In fact, imitation is at the heart of competitive behavior and of almost any kind of social interaction. Like the fixed cost cum marginal cost argument that, as we pointed out earlier, is so powerful an argument that it can be applied to any and every thing, imitation is so widespread that, when taken literally, it is also everywhere. By this token one should see unpriced externalities in every market where producers imitate each other, thereby concluding that all kinds of economic activities should be allowed some form of monopoly power. Restaurants imitate each other, as coffee shops, athletes, real estate agents, car salesmen, and even bricklayers do, but we would certainly find it foolhardy to grant to a firm in each of these businesses monopoly power over one technique or another. This suggests that equating imitation with unpriced externalities leads us into a dark night in which all cows are gray.
Michele Boldrin, Against Intellectual Monopoly
economics