Adam Jaffe

Encouraging inventors to disclose new inventions is an important economic justification for the patent system, yet the technical information contained in patent applications is often inadequate and unclear. This paper proposes a novel approach to measure disclosure in patent applications using algorithms from computation allinguistics. Borrowing methods from the literature on second language acquisition, we analyze core linguistic features of 40,949 U.S. applications in three patent categories related to nanotechnology, batteries, and electricity from 2000 to 2019. Relying on the expectation that universities have more incentives to disclose their inventions than corporations for either incentive reasons or for different source documents that patent attorneys can draw on, we confirm the relevance and usefulness of the linguistic measures by showing that university patents are more readable. Combining the multiple measures using principal component analysis, we find that the gap in disclosure is 0.4 SD, with a wider gap between top applicants. Our results do not change after accounting for the heterogeneity of inventions by controlling for cited-patent fixed effects. We also explore whether one pathway by which corporate patents become less readable is use of multiple examples to mask the "best mode" of inventions. By confirming that computational linguistic measures are useful indicators of readability of patents, we suggest that the disclosure function of patents can be explored empirically in a way that has not previously been feasible.

The 21st century global decline in productivity growth is not well understood. One possible contributor is a decline in economic dynamism. We explore the contribution of firm formation and employee movement to productivity using administrative data on the population of New Zealand construction firms from 2001-2012, along with linked data on their employees and working proprietors, to study the relationships among entry, worker flows and firm productivity. Entrants are more productive than pre-existing firms. Firms that enter and stay exhibit a persistent productivity advantage that averages about seven percent, but which grows as experience accumulates. We find that job churn is prevalent in construction, with around 60 percent of firm-worker pairs not existing previously or not existing subsequently. Firms with new employees are more productive than those with no change in workforce, in part because of knowledge flows from other construction firms. In our preferred specification, with firm fixed effects, a standard deviation increase in the productivity of new employees' previous firms is associated with a 0.6 percent increase in productivity. The entry and worker-knowledge-flow phenomena are distinct, in that the entry effect is not explained by employee composition, and non-entrant firms also benefit from worker knowledge flows

This paper describes the database on U.S. patents that the authors have developed over the past decade, with the goal of making it widely accessible for research. They present main trends in U. S. patenting over the last 30 years, including a variety of original measures constructed with citation data, such as backward and forward citation lags, indices of 'originality' and 'generality', self-citations, etc. Many of these measures exhibit interesting differences across the six main technological categories that they have developed (comprising Computers and Communications, Drugs and Medical, Electrical and Electronics, Chemical, Mechanical and Others), differences that call for further research. To stimulate such research, the entire database about 3 million patents and 16 million citations is now available on the NBER website. They discuss key issues that arise in the use of patent citations data, and suggest ways of addressing them. In particular, significant changes over time in the rate of patenting and in the number of citations made, as well as the inevitable truncation of the data, make it very hard to use the raw number of citations received by different patents directly in a meaningful way. To remedy this problem they suggest two alternative approaches: the fixed-effects approach involves scaling citations by the average citation count for a group of patents to which the patent of interest belongs; the quasi-structural approach attempts to distinguish the multiple effects on citation rates via econometric estimation.

Environmental policy discussions increasingly focus on issues related to technological change. This is partly because the environmental consequences of social activity are frequently affected by the rate and direction of technological change, and partly because environmental policy interventions can themselves create constraints and incentives that have significant effects on the path of technological progress. This paper, prepared as a chapter draft for the forthcoming Handbook of Environmental Economics (North-Holland/Elsevier Science), summarizes for environmental economists current thinking on technological change in the broader economics literature, surveys the growing economic literature on the interaction between technology and the environment, and explores the normative implications of these analyses. We begin with a brief overview of the economics of technological change, and then examine three important areas where technology and the environment intersect: the theory and empirical evidence of induced innovation and the related literature on the effects of environmental policy on the creation of new, environmentally friendly technology; the theory and empirics of environmental issues related to technology diffusion; and analyses of the comparative technological impacts of alternative environmental policy instruments. We conclude with suggestions for further research on technological change and the environment.

As patent data become more available in machine-readable form, an increasing number of researchers have begun to use measures based on patents and their citations as indicators of technological output and information flow. This paper explores the economic meaning of these citation-based patent measures using the financial market valuation of the firms that own the patents. Using a new and comprehensive dataset containing over 4800 U. S. Manufacturing firms and their patenting activity for the past 30 years, the authors explore the contributions of R&D spending, patents, and citation-weighted patents to measures of Tobin's Q for the firms. They find that citation-weighted patent stocks are more highly correlated with market value than patent stocks themselves and that this fact is due mainly to the high valuation placed on firms that hold very highly cited patents.

A survey of recent patentees was conducted to elicit their perceptions regarding the importance of their inventions, the extent of their communication with other inventors, and the relationship of both importance and communication to observed patent citations. A cohort of 1993 patentees were asked specifically about 2 patents that they had cited, and a third 'placebo' patent that was similar but which they did not cite. One of the two cited inventors was also surveyed. The authors find that inventors report significant communication, at least some of which is in forms that suggests spillovers from the cited inventor to the citing inventor. The perception of such communication was substantively and statistically significantly greater for the cited patents than for the placebos. There is, however, a large amount of noise in citations data; it appears that something like one-half of all citations do not correspond to any perceived communication, or even necessarily to a perceptible technological relationship between the inventions. They also find a significant correlation between the number of citations a patent received and its importance (both economic and technological) as perceived by the inventor.

Despite their magnitude and potential economic impact, federal R&D expenditures outside of research universities have been little scrutinized by economists. This paper examines whether the series of initiatives since 1980 that have sought to encourage the patenting and technology transfer at the national laboratories have had a significant impact, and how the features of these facilities affected their success in commercialization. Employing both case studies of and databases about the U.S. Department of Energy's laboratories, the authors challenge much of the conventional wisdom. The policy changes of the 1980s had a substantial impact on the patenting activity by the national laboratories, which have gradually reached parity in patents per R&D dollar with research universities. Using citation data, they show that, unlike universities, the quality of the laboratory patents has remained constant or even increased as their numbers have grown. The cross-sectional patterns are generally consistent with theoretical suggestions regarding the impact and determinants of the decision to privatize government functions.

This paper explores the patterns of citations among patents taken out by inventors in the U.S., the U.K., France, Germany and Japan. The authors 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 approximately 100 times as likely to cite each other as patents from different patent classes there is not a strong time pattern to this effect; (3) patents whose inventors reside in the same country are typically 30 to 80% more likely to cite each other than inventors from other countries, and these citations come sooner; and (4) there are clear country-specific citation tendencies; e.g., Japanese citations typically come sooner than those of other countries.

After examining more than 100 studies, the Economics Resource Group of Cambridge, MA., said, the authors found little evidence to support the view that U.S. environmental regulation had a large adverse effect on competitiveness. The study cited several reasons why there was little indication that the cost of complying with environmental regulations had seriously impacted the competitiveness of U.S. industry. The study contains an executive summary, a summary of most important studies, bibliography (alphabetical and by topic) and abstracts of studies reviewed.