Improving the publication delay model to characterize the patent granting process

Drawing upon the periodical publication delay model and the Weibull distribution model, we develop an improved model and conduct an exploratory analysis to characterize patent grant delay, and learn the crux of the problem. In order to test the effect of the new model, we perform an experiment based on a database of four technological fields from the United States Patent and Trademark Office. The results show that the new model can improve the fitting effect, and is suitable for calculating the time delay between patent application and grant. In addition, we apply the improved model in two different technological fields to study the changing rules in the last two decades by comparing the results, and obtain some valuable information. For a theoretical contribution, we deduce the examination probability under steady-state conditions, extend the periodical publication delay model from a negative exponential distribution to a Weibull distribution, and overcome the shortcomings of the original model.