September 1999 <p> Prepared for a special issue of Research Policy on technology policy issues, forthcoming in the year 2000 under the guest-editorship of Albert N. Link. <p> Is public R&D spending complementary and thus additional to private R&D spending, or does it substitute for and tend to crowd...</p></p>

Revised: March 24, 1999 <p> The original draft of this paper was presented to the American Economic Association Meetings session "In Honor of Edwin Mansfield," held in New York, N.Y., on January 5, 1999. <p> This paper is a first step toward closing the analytical gap in the extensive literature on...</p></p>