The Economics of Improvement in Intellectual Property Law

A number of doctrines in modern copyright and patent law attempt to strikesome balance between the rights of original developers and the rights ofsubsequent improvers. Both patents and copyrights are limited in durationand in scope. Each of these limitations provides some freedom of action tosubsequent improvers. Improvers are free to use material that is in thepublic domain because the copyright or patent has expired. They are free toskirt the edges of existing intellectual property rights, for example bytaking the ideas but not the expression from a copyrighted work or"designing around" the claims of a patent. However, improvers cannot alwaysavoid the intellectual property rights of the basic work on which they wishto improve. Some improvements fall within the scope of the preexistingintellectual property right, either because of an expansive definition ofthat right or because economic or technical necessity requires that theimprover hew closely to the work of the original creator in some basicrespect. Here, the improver is at the mercy of the original intellectualproperty owner, unless there is some separate right that expressly allowscopying for the sake of improvement.