From The Social Science Research Network (SSRN):
Economists have long debated the degree to which inventive and artistic activities were either the result of instinctual urges on the part of creators, or the responses of creators to potential pecuniary rewards. Copyright and patent laws are based on a view that rewards are an important factor. In this paper we attempt to provide an empirical analysis of this question by using a recent data set covering the book production industry. We find evidence that authors publish more new books when they earned higher payments for previously written books, although at high enough levels of payment their production of new works begins to decline, consistent with a backward bending supply function. We also find that few authors are in the backward bending region and that the overall effect of payments to authors is to increase their output. Our results are also consistent with the belief that instinctual elements may play a large role in the creation of books.
Link to the rest at SSRN