This supplement takes as its starting point the way in which applied work in economics came to be dominated by theory after the 1950s. Contributors defend the claim that since the 1970s economics has changed from a field in which the highest-status activity was abstract theorizing to one where doing good applied work is seen as paramount, whether that applied work consists of analyzing data, solving practical problems or giving policy advice. It is now commonplace to argue that empirical work in economics has been transformed by the use of modern computers and the availability of large data sets and that there is more empirical work in the journals. Contributors go against the grain of this argument, contending that the changes in economics run deeper and wider.