Necessity is the Mother of Inventing Around: Edison’s Lamp Patent

Abstract

While some surveys and court cases refer to the practice of “invention around” or “design around,” it is an often-overlooked as a means by which patents promote economic development through competition. We provide the first detailed empirical study of inventing around patent claims in a study of how the enforcement of Edison’s incandescent lamp patent in 1891-1894 stimulated a surge of patenting. Most of these patents disclosed inventions around to that circumvented the Edison patent claims by creating substitute technologies to enable participation in the market. Some of these patents introduced important new technology that became prior art for new fields. This indicates that invention around patents contributes to dynamic efficiency and that it is not necessarily duplicative research. Contrary to widespread understanding, the Edison lamp patent did not suppress technological advance in electric lighting. The market position of General Electric (“GE”), the Edison patent- owner, weakened through the period of this patent’s enforcement.