This paper explores the patterns of citations among patents taken out by inventors in the U.S., the U.K., France, Germany and Japan. We find (1) patents assigned to the same firm are more likely to cite each other, and come sooner than other citations; (2) patents in the same patent class are...

This paper explores the patterns of citations among patents taken out by inventors in the U.S., the U.K., France, Germany and Japan. We find (1) patents assigned to the same firm are more likely to cite each other, and come sooner than other citations; (2) patents in the same patent class are...

This paper surveys the major changes in patent policy and practice that have occurred in the last two decades in the U.S., and reviews the existing analyses by economists that attempt to measure the impacts these changes have had on the processes of technological change. It also reviews the...

Studies of firm-level data have shown that a firm's R&D and the R&D of other firms increase conventional factor productivity. We investigate these phenomena further by examining the relationship between plant-level productivity and firm-level R&D. We find that (1) the productivity-enhancing...

The paper investigates whether patent fees are an effective mechanism to deter the filing of low-quality patent applications. The study analyzes the effect on patent quality of the Patent Law Amendment Act of 1982, which resulted in a substantial increase in patenting fees at the U.S. Patent and...

This paper presents estimates of the depreciation rate of innovations using survey data on revenues associated with Australian patents. Its novelty is twofold. First, it relies on direct observation of the revenue streams of inventions. This is in sharp contrast with previous studies, which all...

A low-quality patent system threatens to slow the pace of technological progress. Concerns about low patent quality are supported by estimates from litigation studies suggesting that the majority of patents granted by the U.S. patent office should not have been issued. This paper proposes a new...