The Effect of File Sharing on Record Sales: An Empirical Analysis
利用实际下载数据，研究文件分享是否减少了音乐的正版销量。通过国际学校假期作为工具变量，发现下载对销量的影响在统计上不显著。
For industries ranging from software to pharmaceuticals and entertainment,\nthere is an intense debate about the appropriate level of\nprotection for intellectual property. The Internet provides a natural\ncrucible to assess the implications of reduced protection because it\ndrastically lowers the cost of copying information. In this paper, we\nanalyze whether file sharing has reduced the legal sales of music. While\nthis question is receiving considerable attention in academia, industry,\nand Congress, we are the first to study the phenomenon employing\ndata on actual downloads of music files.We match an extensive sample\nof downloads to U.S. sales data for a large number of albums. To\nestablish causality, we instrument for downloads using data on international\nschool holidays. Downloads have an effect on sales that is\nstatistically indistinguishable from zero. Our estimates are inconsistent\nWe would like to thank Bharat Anand, Gary Becker, Bob Frank, Shane Greenstein,\nAustan Goolsbee, Alan Krueger, Steven Levitt, Tom Mroz, Alan Sorensen, Joel Waldfogel,\nSteven Wildman, Pai-Ling Yin, participants at numerous seminars, and two anonymous\nreferees for helpful comments. This project would not have been possible without the\nassistance of several individuals and organizations. MixMasterFlame and the FlameNap\nnetwork shared P2P data with us, and BigChampagne LLC, the CMJ Network, Nathaniel\nLeibowitz, and Nevil Brownlee generously provided auxiliary data. We thank Keith Ross\nand David Weekly for assistance in understanding the KaZaA, OpenNap, and WinMX\nsearch protocols and database indices. Sarah Woolverton and Christina Hsiung Chen\nprovided superb research assistance. The financial support of the George F. Baker Foundation\n(Oberholzer-Gee) and the Kenan Faculty Fund (Strumpf) is gratefully acknowledged.\nWe appreciated the aural support from Massive Attack, Sigur Ros, and the Mountain\nGoats.