An Analysis Of Copyright Protrction Stratrgy With Customers Category And Network Externality

With the development of Internet and Science, information product, like computer software and cellphone software, is becoming widespread. Because of high sunk cost and low marginal cost of information product and popularization of Internet, the cost of Information product is becoming low, and piracy is becoming more widespread and harder to stop. This leads to huge loss of the original manufacturer.Piracy is a common problem, and also an important theoretical research subject. Attack and prevent piracy is not only the need of firms to protect himself, but also social responsibility of government and firms. Nowadays information product piracy is becoming general, the piracy rate is different in different country. The firms face the problem of the choice of copyright protection strategy in different country. So, this paper takes the business piracy problem of Information product as research background, and take copyright protection strategy under influence of the piracy as research subject, with game theory as analysis tools, analysis the relation between the original manufacturer and the pirating firms from two aspects such as network effect and the rate of consumer category. We compare two strategy of copyright protection: no copyright protection and setting copyright protection. We address two questions in a monopoly and duopoly setting. Frist, what effects the attractiveness of each of the two strategies? Second, under which conditions will any particular strategy dominate another?This paper sets up on previous research, takes customer classification ratio as endogenous variables. And our paper have two parts:In first part, we assume there is no network effect, In second part, we assume that there exists network effect. At last, we compare the influence of network effect to copyright protection after taking the original customer classification as endogenous variables.