I shall try, in this survey, to show why I think patent statistics are interesting in spite of all the difficulties that arise in their use and interpretation. To do so I shall first describe the nature of patents and the types of data generated by their issuance, their current availability, and some of the major problems that arise when one tries to use them in economic analysis. I shall next review briefly some of the earlier work on this range of issues, focusing particularly on Jacob Schmookler’s work and the questions raised by it. This will be followed by a review of the more modern, “computer age” work of the NBER group (Griliches, Hall, Hausman, Jaffe, Pakes, Schankerman and others), and I shall allude also to similar work of others, especially that of Scherer and the Yale group (Levin, Nelson, Klevorick, Winter, Reiss, Cohen, and others), and the SPRU group (Freeman, Pavitt, Soete, and others). I will not be able to do justice to all of this work (the work of others, of my collaborators, and even my own) but I hope to put up enough guideposts so that the interested reader can find his own way to and through this literature.