Getting into the 'Spirit' of Innovative Things: Looking to Complementary and Substitute Properties to Shape Patent Protection for Improvements

Abstract

This Article both identifies and corrects a blind spot in the literature on optimal patent protection for improvements. Contemporary theories cannot explain why a set of easy cases - cases in which earlier inventors’ patent claims routinely do and should expand over time to encompass later-developed improvements - are easy cases. To explain these cases, patent theory must identify the inventions of earlier and later inventors in a different manner. Today, inventions are viewed simply as innovative things or sets of innovative things. This Article demonstrates that the locus of invention must be identified in a finer-grained manner: the inventions of the successive inventors in an improvement scenario must be identified as the particular properties of innovative things that make them innovative. Identifying innovative properties as the locus of invention has two principal benefits. First, it reduces the explanatory gap between the economic theory on patent protection for improvements and the uncontroversial reality of the contemporary patent regime. It reliably distinguishes the easy cases from the difficult ones, and it explains why the cases are either easy or difficult. Second, it allows the economic concepts of complements and substitutes to be brought to bear on the crafting of optimal claim scope - a task that these concepts have not previously been thought suitable to perform. The easy cases are cases in which the innovative properties of subsequent inventors are pure complements, and the difficult cases are cases in which the innovative properties of subsequent inventors are complement-substitute mixtures.