Patents as a Measure of Innovative Activity
检验美国专利活动能否可靠衡量创新活动，通过构建基于知识、企业规模和专有性的专利生产函数，并与1988年论文的直接创新指标对比，发现专利数量与研发投入、熟练劳动力等的关系与创新活动一致，支持专利作为创新代理变量的有效性。
The authors test whether a measure of patent activity in the United States is a reliable proxy for innovative activity. They introduce a production function for patented inventions based on knowledge, firm size, and the ease of appropriability. The results are then compared with those from their 1988 paper using a direct measure of innovative activity. Patents are found to vary with company R&D, total R&D, and skilled labor in the same manner as does innovative activity. In general, the results support the validity of patent counts as a measure of innovative activity. Copyright 1989 by WWZ and Helbing & Lichtenhahn Verlag AG