Erik Brynjolfsson, Lorin Hitt.Cover title. "An earlier, abbreviated version of the paper was published in the Proceedings of the International Conference on Information Systems, 1993, under the title "Is information systems spending productive? new evidence and new results. Series from publisher's list.Includes bibliographical references (p. 39-40).Supported by the MIT Center for Coordination Science, the MIT Industrial Performance Center, and the MIT International Financial Services Research Center.