Innovation Cycles and Learning at the Patent Office: Does the Early Patent Get the Delay?

We study the relationship between the length of patent review and the importance of inventions. We build a simple model of the U.S. patent review process. Among the model predictions are that, controlling for a patent's position in a new technology cycle, more important innovations would be approved more quickly. Also, the approval delay is likely to decrease as an industry moves from the early stages of an innovation cycle to later stages. These predictions are in line with the evidence we obtain from a data set on U.S. patents granted in the field of genetically modified crops from 1983 to 1999. We also show that failing to account for the innovation lifecycle - as previous studies have done - is likely to bias upwards the estimates of the relationship between delay and importance.