The story of the sewing machine is an important empirical case study of how the American patent system has long dealt with incremental invention and resulting patent thickets. It’s also a self-contained case study, which challenges the principal focus of the literature on recent inventions and recent changes in patent law, such as the rise of biotech patenting since the early 1980s. Given the cutting-edge nature of biotech research and its equally innovative commercialization, this new field presents a moving empirical target for patent scholars and economists. This perhaps explains why recently published studies on patent thickets, at best, have found none, or, at worst, have been inconclusive.
As a single case study, it cannot serve as the basis for drawing definitive conclusions, as more empirical studies will have to be done. The Sewing Machine War, however, does point toward some important lessons for the modern policy debates over patent thickets. One lesson is that the incremental invention of complementary elements of new technology seems to be a common feature of the type of cutting-edge discoveries that the patent system has promoted for more than two hundred years. From the sewing machine to automobiles to airplanes to radios, incremental innovation seems to be omnipresent in the historical evolution of science and technology.
There was even incremental innovation in the invention of the incandescent light bulb, which, contrary to popular myth, was not discovered by Thomas Edison. Just as Isaac Singer invented only the final few elements of a practical and successful sewing machine, Edison invented only the first practical incandescent light bulb. (Of course, both of these were tremendous achievements, and thus this is not meant to denigrate their inventive contributions.) In fact, Edison was even sued for patent infringement by one of the earlier inventors of the light bulb. Unlike Singer