Harhoff, Dietmar; Narin, Francis; Scherer, Frederic M.; … - 1997
Through a survey, economic value estimates were obtained on 962 inventions made in the United States and Germany and on … was subsequently cited. results from two wide-ranging surveys, one in Germany and one in the United States, support … expiration in environments such as Germany with highly progressive annual maintenance fees are more valuable and more highly …
