Barrapunto

No. El estudio no se basa en encuestas

Most of what we know about the effects of file sharing is based on surveys. The evidence is mixed. File sharers generally acknowledge both sales displacement and learning effects, and it is unclear if either effect dominates. Rather than relying on surveys, this study is the first to use observations of actual file-sharing behavior of a large population to assess the impact of downloads on sales. Our dataset includes 0.01% of the world's downloads (1.75 million filetransfers) from the last third of 2002, a period of rapid growth in file sharing. We match audio downloads of users in the United States to a representative set of commercially relevant albums for which we have concurrent weekly sales, resulting in a database of over ten thousand album- weeks. This allows us to directly study the relationship between downloads and sales. To establish causality, we instrument for downloads using international school holidays, a supply shock that is plausibly exogenous to sales. Our instruments are relevant since they have a large impact on file transfer time, which in turn is a key determinant of the number of downloads.

básicamente comparan canciones bajadas, no preguntando sino leyendo el tráfico de dos servidores openNap, con las cifras públicas de ventas semanales de discos