Original sentence: Since a non-rival good may be used (copied, for example) by many simultaneously (produced at zero marginal cost in economic terms), producers would have no incentive to create such works.Since the trade-off and the relevant benefits and costs to society will depend on many factors that may be specific to each product and society, the optimum period of time during which the temporary monopoly rights exist is unclear.The establishment of intellectual property rights therefore represents a trade-off, to balance the interest of society in the creation of non-rival goods (by encouraging their production) with the problems of monopoly power
Edited sentence: Since a non-rival good may be used (copied, for example) by many simultaneously (produced at zero marginal cost in economic terms), some believe that producers would have no incentive to create such works.Since the trade-off and the relevant benefits and costs to society will depend on many factors that may be specific to each product and society, the optimum period of time during which the temporary monopoly rights exist is disputed.The establishment of intellectual property rights therefore represents a trade-off, to balance the interest of society in the creation of non-rival goods (by encouraging their production) with the problems of monopoly power and the freedoms of the public.There are other incentives to produce besides economic ones