What is the Impact of Software Patent Shifts?: Evidence from Lotus v. Borland

Economists have debated the extent to which strengthening patent protection spurs or detracts from technological innovation. In this paper, we examine the reduction of software copyright protection in the Lotus v. Borland decision. If patent and copyright protections are substitutes, then weakening of one form of protection should be associated with an increasing reliance on the other. We find that the firms affected by the diminution of copyright protection disproportionately accelerated their patenting in subsequent years. But little evidence can be found for harmful effects: in fact, the increased reliance on patents is correlated with some positive outcomes for firms.