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Chapter 5. Academic Research and Development

Outputs of S&E Research: Articles and Patents

Chapter 2 of this volume discusses the human capital outputs of higher education in S&E. This section continues that theme by examining the intellectual output of academic S&E research using indicators derived from published research articles and U.S. patent and related data.

Researchers have traditionally published the results of their work in the world's peer-reviewed S&E journals.[24] Article-level data from these journals are indicators of S&E research output by countries and—within the United States—by academia and other sectors of the economy.[25] (See sidebar "Bibliometric Data and Terminology.") These bibliometric data can also be used to track trends in S&E research collaboration, using measures of coauthorship between and among departments, institutions, sectors, and countries. Finally, citations in more current research articles to previous research, and in patents to published research articles, offer insight into the importance and impact of previous research and its connection to inventions.

S&E Article Output

Between 1999 and 2009, the total world S&E article output in the SCI/SSCI database grew at an average annual rate of 2.6% (table 5-17). Leading this growth was China at 16.8% per year, which propelled it from ninth largest S&E article producer[26] in 1999 to second largest in 2009 behind the United States. Very rapid growth of over 10% per year was also experienced by South Korea and, from low bases, by Iran, Tunisia, Thailand, Pakistan, and Malaysia.

Viewed regionally, growth in S&E article output over the decade has been uneven. Mature economies had modest growth or decline: the United States averaged 1.0%, EU member countries 1.4%, while Japan declined by –1.1% per year and Russia by –2.0%. Developing economies, mainly in Asia, far outpaced this growth in S&E articles, where China (16.8%) and South Korea (10.1%) were joined by Taiwan at 7.7%, Singapore at 8.2%, and India at 6.9% (table 5-17 and appendix table 5-27).

The research portfolios of the U.S., EU, and Asian economies differ in important ways (NSB 2010; and appendix tables 5-27 through 5-40):

  • China and Japan emphasize the physical sciences more than the United States and European Union;
  • The United States, European Union, and Japan produce relatively more articles in the life sciences than China or other Asian nations; and
  • S&E research publications with authors in Asian countries are more heavily concentrated in engineering than those with authors in the United States or European Union.

Countries in Central and South America together increased their S&E article output between 1999 and 2009 at an annual rate of 5.6%. Brazil had the highest growth rate in the region, at 7.7% (table 5-17 and appendix table 5-27).

The countries or other entities with indexed S&E articles are always evolving.[27] In the current volume, 199 receive credit for publishing S&E articles (appendix table 5-25). Of these, a small number account for most of the publications.[28] Table 5-17 shows that five countries (the United States, China, Japan, the United Kingdom, and Germany) accounted for more than 50% of the total world S&E article output in 2009. The 49 countries in table 5-17—one quarter of the countries in the data—produced 98% of the world total of S&E articles.

The number of journals covered by SCI/SSCI has expanded to accommodate the rising number of research articles. Most of the increase reflects activity in new S&T centers. Figure 5-22 shows how the number of published articles has grown over the past 20 years, from 485,000 articles in 1989 to 788,000 in 2009. Non-U.S. articles have increasingly dominated world S&E article output, growing from 63% to 74% of the total. The expansion of non-U.S. S&E articles signals the return on decades of increased investments in higher education and the more recent conviction that R&D is essential to economic growth and competitiveness. It also reflects a slowdown in the growth of U.S. S&E article output to around 1% or less in recent years.

In Figure 5-22, co-authored articles are pro-rated to U.S. sectors and foreign countries, depending on their fraction of the institutional addresses. These fractions were then re-summed to produce the shares shown in the figure. But that method of allocating credit for S&E article authorship does not show the relationships among the authors, author sectors, and country authors that together illuminate the extent to which S&E research is an increasingly global, collaborative undertaking. The following sections explore these growing collaborative and international dimensions of world S&E research as indicated by data on S&E publications. Together these indicators will describe a growing globalization of the social system of scientific knowledge production and the global use of its outputs.

Coauthorship and Collaboration

Article output trends since about the mid-1990s have two defining features: the rapid growth of articles with authors from the developing world, and a rise in the percentage of global article output that is the result of collaboration among researchers internationally. Articles with authors from different institutions in the United States and from different countries have continued to increase, indicating rising knowledge creation, transfer, and sharing among institutions and across national boundaries.[29],[30] This section covers broad trends in coauthorship for the world as a whole and continues with an examination of country-level trends, including selected country-to-country coauthorship patterns and indexes of international collaboration.[31] Indicators of cross-sector coauthorship, which are available only for the United States, are examined below in the section "Trends in Output and Collaboration Among U.S. Sectors."

Article Author Names and Institutions

Earlier volumes of this report have noted the imbalance between the growth in number of S&E articles and the growth in the number of authorship credits to institutions and individuals that produced those articles (NSB 2008, 08-01, figure 5-29; NSB 2010, 10-01, table 5-16). The much faster growth in authorship credits to institutions and individuals—in all broad fields—has been used as an indicator of a steady rise in the collaborative nature of S&E research, both domestically and internationally.

Figure 5-23 shows the same trend, but here data are restricted to articles with at least one U.S. academic author. Over the period 1990–2010, the number of such articles in the data analyzed in this section increased by an average of 1.6% annually. In contrast, the number of institutions listed on these articles grew over twice as fast at 4.1% annually, and the number of author names grew even faster, at 4.4% annually.

Figure 5-24 focuses on the authors per paper for S&E articles by field with an author from the U.S. academic sector over the same 20-year period. In two decades, the average number of author names per paper in all S&E fields grew from 3.2 to 5.6. The average number of authors per paper more than quadrupled in astronomy (3.1 to 13.8) and doubled in physics (4.5 to 10.1). Growth in the average number of coauthors was slowest in the social sciences (from 1.6 authors per paper in 1990 to 2.1 in 2010) and in mathematics (from 1.7 to 2.2). In short, papers authored by a single U.S. academic scientist or engineering are becoming an increasingly small minority of the published literature. NSF analysis shows that in 2010, 92.4% of all S&E articles with at least one U.S. academic author had two or more author names.

A closely related indicator, coauthored articles (i.e., articles with authors in different institutions or departments or in more than one country) has also increased steadily. Figure 5-25 contrasts these trends for the world as a whole with those for articles with at least one U.S. academic author. Coauthored articles grew from 42% of the world's total S&E articles in 1990 to 67% in 2010. This growth has two parts. Coauthored articles that list only domestic institutions grew from 33% of all articles in 1990 to 43% in 2010. Articles that list institutions from more than one country, that is, internationally coauthored articles (which also may have multiple domestic institutional authors), grew more dramatically—from 10% to 24% over the same period.

The percent of S&E articles with a U.S. academic author that is internationally coauthored is higher than the percent of total world international coauthorships (figure 5-25). Purely domestic coauthorship in this sector has been relatively flat in the United States, at about 43% of total U.S. academic articles from 1990 to 2010. Over the same period U.S. academic articles with a non-U.S. coauthor have grown strongly, from 12% to 32%. (These coauthorships may also include multiple domestic U.S. coauthors.) The remainder of this section takes a closer look at patterns within this broad increase in international coauthorship around the world.

International Coauthorship Patterns From a Country Perspective

International coauthorship can be considered from two perspectives: (1) a country's level of participation in the world's total S&E coauthorships, and (2) a country's international coauthorship vis-à-vis the country's total S&E authorship.

World total S&E coauthorship. Table 5-18 shows the world's countries/economies that account for 1% or more of internationally coauthored S&E articles, and how their relative standing, or rank, has changed over the past 10 years. U.S.-based researchers were coauthors of 43% of the world's total internationally coauthored articles in 2010, well above the global percentage of U.S. article output. Germany, the United Kingdom, and France were also leading contributors to the world's internationally coauthored articles. The most notable trend in this indicator, however, was the rise of authors from China, who increased their share of world internationally coauthored S&E articles from 5% to 13% over the last 10 years.

Individual region/country coauthorship. Table 5-19 compares a region/country's share of total world international coauthorship with the region/country's internal or domestic rate of international coauthorship. The table is restricted to countries that had institutional authors on at least 5% or more of the world's internationally coauthored S&E articles in 2010 (see also appendix table 5-41).

The sheer volume of U.S. internationally coauthored articles dominates these measures: 32% of U.S. articles in 2010 were internationally coauthored, up from 23% in 2000. Even higher rates of international coauthorship are evident among the countries of the European Union, where large Framework Research Programs have strongly encouraged it, and in Switzerland. Both Japan's and Asia-8's international coauthorship rates have increased over the past 10 years, and more countries passed the 50% mark over the decade.

Table 5-19 also shows China's idiosyncratic position on this indicator. Table 5-17 shows that China's S&E article output grew sufficiently over the decade to place it as the world's second largest S&E article-producing nation. At the same time, China's internationally coauthored articles as a share of its total article output remained almost flat and, at 27%, was the lowest percentage of all countries/regions shown on Table 5-19. This atypical measure shows that China's very rapid S&E article growth has been driven by articles with solely domestic authors (see discussion below of China's rates of internal and international citations).

What accounts for specific coauthorship relationships? Linguistic and historical factors (Narin et al. 1991), geography, and cultural relations (Glänzel and Schubert 2005) play a role. In recent years, coauthorships in Europe have risen in response to EU policies and incentives that actively encouraged intra-European cross-border collaboration. However, strong ties among science establishments in the Asian region, without the formal framework that characterizes Europe, indicate that regional dynamics can play a strong role in the development of collaborative ties. The discussion below in the section "International Collaboration in S&E" identifies strong coauthorship relationships in specific country pairs across the world, based on the strength of their coauthorship rates.

International Coauthorship With the United States

Table 5-20 lists the 31 countries whose institutions appeared on at least 1% of U.S. internationally coauthored articles in 2010. U.S. authors are most likely to coauthor articles with colleagues from the United Kingdom (14.1%), China (13.7%), Germany (13.3%), and Canada (11.8%).

Table 5-19 shows that the rate at which U.S. researchers participate in international collaboration is below that of many countries with smaller science establishments. The large size of the U.S. S&E establishment results in a share of U.S. internationally coauthored articles that is lower than those of most other countries. Scientists and engineers in countries with smaller S&E establishments, in order to find an appropriate coauthor, must more frequently turn to coauthors abroad, resulting in relatively larger shares of those countries' S&E articles that are coauthored with U.S. scientists and engineers. These relationships are summarized in table 5-20.

For example, 2.8% of U.S. internationally coauthored articles in 2010 had an Israeli coauthor. The corresponding figure for Israel, with its much smaller scientific infrastructure, is 53.9%. Also, 49.9% of Canada's internationally coauthored articles had a U.S. coauthor, but only 11.8% of U.S. international coauthorship was with a colleague at a Canadian institution.[32] Linguistic, geographic, and other ties underlie these collaborations.

Notable changes in these patterns of U.S. international coauthorship parallel changes in other indicators discussed in this section. As China's total S&E article output grew rapidly, so did its coauthorship with U.S. authors: the U.S. share of China's internationally coauthored articles increased about 10 percentage points to 45.2% over the past decade, and China's share of U.S. internationally coauthored articles increased 9.7 percentage points to 13.7% (table 5-20). In contrast, U.S. scientists and engineers lost relative share of international coauthorship elsewhere (e.g. Japan, Australia, Taiwan, and South Korea) as their counterparts broadened the geographic scope of their collaborations with foreign scientists and engineers.

An Index of International Collaboration in S&E

The size of countries' S&E systems conditions the scope and reach of their international collaborations (Glänzel and Schubert 2004). An index of international collaboration addresses this issue. This index is a ratio of country A's percentage of country B's international coauthorships to country A's percentage of total international coauthorship (Narin et al. 1991) (see sidebar, "Calculating the Index of International Collaboration"). An index value substantially greater than 1 indicates strong collaborative ties, and a value substantially below 1 signals relatively infrequent collaboration. The 1995 and 2010 indexes for country pairs that produced more than 1% of all internationally coauthored articles in 2010 are shown in appendix table 5-42.

Table 5-21 lists the international collaboration index for selected pairs of countries. In North America, the Canada-United States index shows a rate of collaboration that is slightly greater than would be expected based solely on the number of internationally coauthored articles produced by these two countries, and the index has changed little over the past 15 years. The United States-Mexico index is just about as would be expected and is also stable.

Mexico-Argentina scientific collaboration networks are strong at 3.5, well above expected levels. In South America, the collaboration index of Argentina-Brazil, at 5.1, is one of the highest in the world.

Collaboration indexes between pairs of countries on opposite sides of the North Atlantic are all low and have changed little over the past 15 years. In Europe, collaboration patterns are mixed but most have increased, indicating growing integration across the European Union for S&E article publishing. Among the large publishing countries (Germany, the United Kingdom, and France) collaboration was less than expected, but grew in all three countries over 15 years. A particularly strong collaboration network has developed between scientists in Poland and the Czech Republic.

The Scandinavian countries[33] increased their collaboration indexes with many countries elsewhere in Europe (appendix table 5-42). Within Scandinavia, the indexes are among the highest in the world (table 5-21).

Cross-Pacific collaboration patterns are mixed. Japan-United States collaboration fell below the expected value over the 15 years, while the United States-China index rose to 1. U.S. collaboration with South Korea and Taiwan weakened but remained higher than expected in both cases. The international collaboration indexes between Canada and countries in Asia are lower than the U.S.-Asia indexes.

Collaboration indexes within Asia and across the South Pacific between the large article producers are generally higher than expected, but have experienced some weakening. Australia's coauthorships are strongly linked to New Zealand. Two strongly collaborating pairs are South Korea-Japan and Australia-Singapore, but each of these networks has declined in strength. India's collaborations with both South Korea and Japan grew stronger between 1995 and 2010.

Trends in Output and Collaboration Among U.S. Sectors

In the U.S. innovation system, ties between and among universities, industry, and government can be beneficial for all sides. These ties include the flows of knowledge among these sectors, for which research article outputs and collaboratively produced articles are proxy indicators. S&E articles authored at academic institutions have for decades accounted for more than 70% of all U.S. articles, and this percentage has been slowly rising—to 76% in 2010 (table 5-22), primarily as a result of declines in articles with authors from industry (for a discussion of this shift, see NSB 2008). This section contrasts U.S. academic authorship with nonacademic authorship, including output trends by sector and trends in coauthorship, both between U.S. sectors and between U.S. sectors and authors abroad.

Article Output by Sector

Total annual S&E articles by authors in U.S. nonacademic sectors changed little over the past decade, ranging from 48,000 to 55,000 articles[34] per year between 1995 and 2010 (appendix table 5-43). The number of articles produced by scientists and engineers in the federal government and in industry was more than 15,000 in each sector in 1995 but slowly declined through 2010, and each sector lost share over that period (table 5-22). State and local government authorship, dominated by articles in the medical and biological sciences, has remained constant. Scientists and engineers in the private nonprofit sector increased their output to about 18,000 in 2008 and then declined to near 17,000 in 2010 (appendix table 5-43).

Federally funded research and development centers (FFRDCs) are research institutions that are sponsored by federal agencies and administered by universities, industry, or other nonprofit institutions. FFRDCs have specialized research agendas closely related to the mission of the sponsoring agency and may house large and unique research instruments not otherwise available in other research venues. Although authors at FFRDCs published articles in all of the broad S&E fields considered in this chapter, articles in physics, chemistry, and engineering together represented 71% of publication by this sector in 2010, reflecting the more specialized research programs in FFRDCs (appendix table 5-43).[35]

In contrast, articles published by authors in the private nonprofit sector are primarily in the medical sciences (54% of the sector's articles in 2010) and biological sciences (25%) (appendix table 5-43). Federal government authors show a similar pattern, with 30% in the biological sciences and 28% in the medical sciences.

Trends in Sector Coauthorship

Coauthorship data are indicators of collaboration at the sectoral level between U.S. institutional authors and between U.S. sectors and foreign institutions.[36] These data show that the growing integration of R&D activities, as measured by coauthorship, is occurring across R&D-performing U.S. institutions in all sectors.

Overall, the largest increases in this integration have been driven by increased coauthorship between U.S. academic authors and non-U.S. authors (in all sectors; NSF data do not identify the sectors of non-U.S. authors) (table 5-23). Co-authorship between non-U.S. authors and U.S. academic authors increased over the decade by 9.9 percentage points.

Between 2000 and 2010, coauthorship within sectors increased for all U.S. sectors.[37] Coauthorship within academia rose from 39% in 2000 to 47% in 2010. FFRDC to FFRDC coauthorship increased 6 percentage points (table 5-23). Because most publishing scientists and engineers are in the academic sector, non-academic scientists and engineers turn to academia for collaborators, so the resulting rates of cross-sector coauthorship with academic authors are quite high and continue to increase. Because of the predominance of the academic sector in S&E article publishing in the United States, academic scientists and engineers have been on the forefront of integrating S&E research across institutions, both nationally and internationally.

As discussed earlier in this chapter, international collaboration has increased rapidly in the United States. International coauthorship across the U.S. sectors rose by 7–11 percentage points between 2000 and 2010 (table 5-23). Articles from FFRDCs reached the highest rate of collaboration with foreign authors, at 46%, followed by those from academia, private nonprofit institutions, industry, and the federal government, at roughly 30% each.

Trends in Citation of S&E Articles[38]

Citations indicate influence, and they are increasingly international in scope. When scientists and engineers cite the published papers resulting from prior S&E research, they are formally crediting the influence of that research on their own work.[39] Citations are generally increasing in volume relative to S&E articles. In 1992, an S&E article received, on average, 1.85 citations. In contrast, an S&E article in 2010 received on average 2.32 citations (Figure 5-26). Articles with U.S. authors tended to receive more citations than others, but the gap narrowed over the period as the total share of U.S.-authored articles declined.[40]

Like the indicators of international coauthorship discussed above, cross-national citations are evidence that S&E research is increasingly international in scope. Two other trends accompanied the steady growth of international citations in the world's S&E literature: changing shares of total citations across countries and changing shares of highly cited S&E literature. These are discussed in the following sections.

Citation Trends in a Global Context

Shares of the world total of citations to S&E research articles have changed concurrently with shares of the world total of these articles. Table 5-24 shows, for example, that between the periods 1996–98 and 2006–08, the U.S. share of world S&E articles declined from 32% to 28% across all fields.[41] The U.S. share declined in every broad field, although the decline varied in size. Table 5-24 shows parallel trends for the U.S. share of citations and indicates an even larger decline, from 45% to 36%.

China's share of total world S&E articles and citations increased over the same period. However, in contrast to the global trend of increasing international citations, China's pattern has been different. Unlike the United States and other large article-producing countries/regions, the share of China's citations that are international citations decreased between 2000 and 2010, from 60% to 51% (figure 5-27), suggesting that much of the use of China's expanding S&E article output—as indicated by citations to those articles—is occurring within China.[42]

Trends in Highly Cited S&E Literature

Another indicator of performance of a national or regional S&E system is the share of its articles that are highly cited. High citation rates can indicate that an article has a greater impact on subsequent research than articles with lower citation rates.

Appendix table 5-44 shows citation percentiles for 2000 and 2010 by field for the top five S&E article-producing countries/regions.[43] In that table, a country whose global research influence was high would have higher proportions of articles in higher citation percentiles, whereas a country whose influence was low would have greater proportions of articles in lower citation percentiles. In other words, a country whose research is highly influential would have higher shares of its articles in higher citation percentiles.

World citations to U.S. research articles show that U.S. articles continue to have the highest citation rates across all broad fields of S&E. In both 2000 and 2010, as displayed in appendix table 5-44, the U.S. share of articles in the 99th percentile was higher than its share in the 95th percentile, and these were higher than its share in the 90th percentile, and so forth, even while U.S. shares of all articles and all citations were decreasing. In 2010, U.S. articles represented 28% of the world's total of 2.3 million articles in the cited period shown; the U.S. authored 49% of the rare 21,900 articles in the 99th percentile and 24% of the 1.3 million articles in the 50th percentile.

Only U.S. publications display the preferred relationship of strongly higher proportions of articles in the higher percentiles of article citations. When cited, articles with authors from the European Union, China, Japan, and the Asia-8 are more often found in the lower citation percentiles. (These data are summarized in appendix table 5-45.) Nevertheless, as the U.S. share of all articles produced declined between 2000 and 2010, its share of articles in the 99th percentile (i.e., the top 1%) of cited articles also declined, particularly in some fields. Shares in the top percentile increased for the European Union, China, Japan, and the Asia-8.

To control for changing shares of the world's S&E articles, Figure 5-28 shows the percentage of total articles for each of the United States, European Union, and China that appears in the world's top 1% of cited articles. Across the decade, 1.6%–1.8% of U.S.-authored S&E articles have appeared in the world's top 1% of cited articles, compared with 0.7%–0.9% of articles from the EU. China's articles in the top 1% of cited articles remained behind the United States and European Union but increased from 0.1% to 0.5% over the period.

When citation rates are normalized by the share of world articles during the citation period to produce an index of highly cited articles, the influence of U.S. articles has changed little over the past 10 years. Between 2000 and 2010, the U.S. index of highly cited articles barely changed (from 1.85 to 1.76) (figure 5-29 and appendix table 5-45) and remained well above the expected index value of 1. During the same period, the EU increased its index from 0.73 to 0.93, and China, Japan, and the Asia-8 increased their index values but remained below their expected values. In other words, the United States had 76% more articles than expected in the 99th percentile of cited articles in 2010, and the EU had 7% fewer than expected. China had 51% fewer articles in the 99th percentile than expected in 2010, and Japan 39% fewer.

The United States experienced gains on the index of highly cited articles in engineering, astronomy, other life sciences, and psychology and declines in chemistry, geosciences, and mathematics, although all remained well above expectation (appendix table 5-45). The EU reached its expected value in engineering, chemistry, physics, and the agricultural sciences. Japan and the Asia-8 countries did not achieve the expected value of 1 in any broad field.

Notably, China achieved an index value of near 1 in engineering and computer sciences (figure 5-30). In most broad fields, China's indexes of highly cited articles were higher in 2010 than in 2000. In a few fields—the biological, medical, and social sciences—the Chinese index remained low, and these fields kept the index for all fields below 0.5 in 2010 (appendix table 5-45).

Academic Patents, Licenses, Royalties, and Startups

Other indicators of academic R&D outputs reflect universities' efforts to develop their intellectual property for possible commercial use in the form of patents and associated activities. The majority of U.S. universities did not become actively involved in managing their own intellectual property until late in the 20th century, although some were granted patents much earlier.[44] The Bayh-Dole Act of 1980 gave colleges and universities a common legal framework for claiming ownership of income streams from patented discoveries that resulted from their federally funded research. To facilitate the conversion of new knowledge produced in their laboratories to patent-protected public knowledge that can be potentially licensed by others or form the basis for a startup firm, more and more research institutions established technology management/transfer offices (Association of University Technology Managers 2009).

The following sections discuss overall trends in university patenting and related indicators through 2009–10.

University Patenting Trends

U.S. Patent and Trademark Office (USPTO) data show that annual patent grants to universities and colleges ranged from 2,900 to 4,500 between 1998 and 2010 (appendix table 5-46).[45]

The top 200 R&D-performing institutions, with 97% of the total patents granted to U.S. universities during the 1998–2010 period, dominate among universities and university systems receiving patent protection.[46] College and university patents have been about 4.2–4.7% of U.S. nongovernmental patents for a decade. Among the top R&D-performing institutions that received patents between 1998 and 2010, 19 accounted for more than 50% of all patents granted to these institutions (although these included a few multicampus systems, including the Universities of California and Texas). The University of California system received 11.9% of all U.S. patents granted to U.S. universities over the period, followed by the Massachusetts Institute of Technology with 4.2% of all U.S. patents granted to U.S. universities.

Biotechnology patents account for the largest percent (30%) of U.S. university patents in 2010 (appendix table 5-47), and have grown over the past 15 years (figure 5-31). Pharmaceutical patents, the next largest technology area, have more recently begun to decline, from nearly 450 a year in the late 1990s to about 300 in more recent years. Patents for measuring devices, semiconductors, and optics have all increased gradually over the past two decades.

Patent-Related Activities and Income

Data from the Association of University Technology Managers (AUTM) indicate continuing growth in a number of patent-related activities. Invention disclosures filed with university technology management offices describe prospective inventions and are submitted before a patent application is filed. These grew from 12,600 in 2002, to 18,200 in 2009 (notwithstanding small shifts in the number of institutions responding to the AUTM survey over the same period) (figure 5-32). Likewise, new U.S. patent applications filed by AUTM university respondents also increased, from 6,500 in 2001, to 11,300 in 2009. U.S. patents awarded to AUTM respondents stayed flat over the period, at about 3,000 per year with some fluctuation.[47]

The AUTM survey respondents reported 348 startup companies formed in 2003 and 555 in 2009, with a total of extant startup companies in 2009 of 3,175 (appendix table 5-48). Licenses and options that generated revenues also increased over the period. However, active licenses, while increasing steadily from 1999 to 2008, declined slightly in 2009; this decline may reflect the downturn in the U.S. economy in that period.

Most royalties from licensing agreements accrue for relatively few patents and the universities that own them, and many of the AUTM respondent offices report no income. (Thursby and colleagues [2001] report that the objectives of university technology management offices include more than royalty income.) At the same time, large one-time payments to a university can affect the overall trend in university licensing income. In 2009, the 153 institutions that responded to the AUTM survey reported a total of $1.5 billion in net royalties from their patent holdings, down sharply from the previous 2 years, perhaps as a result of the nation's economic downturn in 2008–09 (appendix table 5-48).

Patent-to-Literature Citations

Citations to the S&E literature on the cover pages of issued patents are one indicator of the contribution of research to the development of practical innovations.[48] This indicator of how science links to invention increased sharply in the late 1980's and early 1990's (Narin, Hamilton, and Olivastro 1997), due in part to developments in U.S. policy, industry growth and maturation, and court interpretation. At the same time, patenting activity by academic institutions was increasing rapidly, as were patent citations to S&E literature produced across all sectors (NSB 2008, pp. 5-49 to 5-54).

Between 1998 and 2010, growth for this indicator was much slower. Of utility patents awarded to both U.S. and foreign assignees, 11% cited the S&E articles analyzed in this chapter in 2010 (appendix table 5-49). Concomitant with a growth in the percentage of U.S. utility patents awarded to foreign assignees, nearly 50% of the citations to the S&E literature in 2010 cited non-U.S. S&E articles.

In 2010, five broad S&E fields (biological sciences, medical sciences, chemistry, physics, and engineering) accounted for 96% of the citations to U.S. articles in USPTO patents (figure 5-33 and appendix table 5-50). These citations are dominated by articles in the biological sciences, at 46% of the total (compare with patents awarded by technology area, figure 5-31).

Considering only citations to U.S. articles, growth in citations has been uneven across the sectors and thus sector shares have changed somewhat (appendix table 5-49). Citations to articles authored in the industry, nonprofit, and government sectors have lost share, largely to articles from academia, which grew from 58% to 64% of the total citations to U.S. articles between 1998 and 2010. Appendix table 5-50 summarizes the increasing role of citations to U.S. academic articles in the science linkage to U.S. patents. Of the five broad fields of S&E that accounted for virtually all patent citations to U.S. academic articles, increased shares of academic citations were notable in engineering (from 46% to 63%) and physics (from 43% to 66%).

Figure 5-34 shows, within the most cited S&E fields, the distribution by U.S. sector of citations to articles in U.S. patents in 2010. As noted above, academic articles dominate across all of the fields shown, from 62% in the biological sciences to 68% in chemistry. U.S. government-authored articles received 7% of the 2010 patent citations in both the biological and medical sciences. S&E articles from industry accounted for 27% of the engineering citations and about one-fifth of the articles cited in chemistry and physics. FFRDC-authored articles accounted for 6% of the physics citations.

Energy and Environment-Related Patent Citations

NSF developed a set of four filters for identifying patents with potential application in pollution mitigation and in alternative means of energy production, storage, and management. (See sidebar "Identifying Clean Energy and Pollution Control Patents" for details on the filters.) These include patents slated by the federal government for fast-track review at USPTO.[49]

Chapter 6 of this volume presents extensive data on the patents in these four technology areas, including the nationality of their assignees. (See chapter 6, "Patenting of clean energy and pollution control technologies.") This section reports on the citations in those patents to the S&E literature, using those citations to indicate the linkages between S&E R&D[50] and the potential for practical use of the results of those R&D projects in new inventions and technologies.

Five broad S&E fields dominate the citations to S&E literature in these four patent areas: chemistry, physics, engineering, the biological sciences, and geosciences (which in this taxonomy includes the environmental sciences). The range of S&E fields cited indicates that these developing technologies rely on a wide base of S&E knowledge.[51]

The S&E fields cited by these patents are shown in table 5-25. Thirty-five percent of the citations in alternative energy patents that cite S&E articles were to chemistry articles, followed by articles from physics (28%), engineering (20%), and the biological sciences (15%).

Chemistry also dominates the citations in patents for energy storage systems, at 54%., followed by citations to articles in engineering (20%), physics (16%), and the biological sciences (9%).

Patents with potential for application in pollution mitigation processes cite S&E articles most often in chemistry, at 31%. The biological sciences, geosciences, and engineering each receive about one-fifth of the citations in these patents.

Smart grid is a set of patents related to efficient use and distribution of energy. Two fields dominate the S&E article citations in these patents: physics (52%) and engineering (40%).


[24] Publication traditions in broad S&E fields differ somewhat. For example, computer scientists often publish their findings in conference proceedings, and social scientists often write books as well as publish in journals. Proceedings and books are poorly covered in the data currently used in this chapter.
[25] The U.S. sector identification in this chapter is quite precise; to date, sector identification has not been possible for other countries.
[26] Statements that a country "authors" a certain number of articles are somewhat imprecise, especially given the growing rates of international collaboration discussed later in this chapter. This chapter follows the convention of counting a country's articles in fractions (i.e., articles with more than one country's participation are fractionalized according to the number of different institutional authors listed on the article). These fractions are then allocated to the respective country and totaled to produce a national article count. This chapter uses the more straightforward if less precise terminology "country X produces some number of the world's S&E articles." It also refers to the percentage of the world's total S&E articles accounted for by certain countries.
[27] For example, Vatican City is not strictly a country; the Union of Soviet Socialist Republics (USSR) and Hong Kong are contained in the data in earlier years, but the USSR no longer exists and Hong Kong data are now reported as part of China. See appendix table 5-25 for a list of the locations represented in the data.
[28] Distributions of data in which a small percentage of cases account for a significant amount of the total value across all cases belong to a group of statistical distributions collectively referred to as power law distributions (Adamic, 2000). Examples of other phenomena with such distributions include earthquakes (only a few among a large number of earthquakes have great power) and Internet traffic (visits to a relatively small number of sites account for a very large proportion of visits to all sites).
[29] Coauthorship is a broad, though limited, indicator of collaboration among scientists. Previous editions of Indicators discussed possible underlying drivers for increased collaboration, including scientific advantages of knowledge- and instrument-sharing, decreased costs of travel and communication, and national policies (NSB 2006). Katz and Martin (1997), Bordons and Gómez (2000), and Laudel (2002) analyze limitations of coauthorship as an indicator of research collaboration. Despite these limitations, other authors have continued to use coauthorship as a collaboration indicator (Adams et al. 2005; Gómez, Fernández, and Sebastián 1999; Lundberg et al. 2006; Wuchty, Jones, and Uzzi 2007; Zitt, Bassecoulard, and Okubo 2000).
[30] The reader is reminded that the data on which these indicators are based give the nationality of the institutional addresses listed on the article. Authors themselves are not associated with a particular institution and may be of any nationality. Therefore the discussion in this section is based on the nationality of institutions, not authors, and makes no distinction between nationality of institutions and nationality of authors.
[31] For a consideration of current limitations in identifying interdisciplinary S&E research using bibliometrics techniques, see Wagner et al. (2011) and the sidebar "Can Bibliometric Data Provide Indicators of Interdisciplinary Research?" in NSB 2010.
[32] Readers are reminded that the number of coauthored articles between any pair of countries is the same; each country is counted once per article in these data. However, countries other than the pairs discussed here may also appear on the article.
[33] Finland is included here as one of the Scandinavian countries. Iceland is not.
[34] Article counts in this section are based on the year in which the article appeared in the database, not on the year of publication, and therefore are not the same counts as in the earlier discussion of total world article output.
[35] The 16 FFRDCs sponsored by the Department of Energy dominated S&E publishing by this sector. Across all fields of S&E, DOE-sponsored labs accounted for 83% of the total for the sector in 2005 (NSB 2008). Scientists and engineers at DOE-sponsored FFRDCs published 96% of the sector's articles in chemistry, 95% in physics, and 90% in engineering (see "S&E Articles From Federally Funded Research and Development Centers," NSB 2008, p. 5–47). Nine other federal agencies, including the Departments of Defense, Energy, Health and Human Services, Homeland Security, Transportation, and Treasury; the National Aeronautics and Space Administration; the Nuclear Regulatory Commission; and National Science Foundation also sponsor another 23 FFRDCs (NSF/SRS 2009).
[36] Identification of the sector of the non-U.S. institution is not possible with the current data set.
[37] Readers are reminded that coauthors from different departments in an institution are coded as different institutions.
[38] This chapter uses the convention of a 3-year citation window with a 2-year lag. For example, 2008 citation rates are from references in articles in the 2008 data file to articles contained in the 2004, 2005, and 2006 data files of the Thomson Reuters Science Citation Index and Social Sciences Citation Index databases. Analysis of the citation data shows that, in general, the 2-year citing lag captures the 3 peak citation years for most fields, with the following exceptions: in astronomy and physics, the peak citation years are generally captured with a 1-year lag, and in computer sciences, psychology, and the social sciences with a 3-year lag.
[39] "Influence" is used here broadly; even citations that criticize or correct previous research indicate the influence of that previous research on the citing article.
[40] Because different S&E fields have different citation behaviors, these indicators should be used with caution. For example, articles in the life sciences tend to list more references than, for example, articles in engineering or mathematics. Thus, a country's research portfolio that is heavily weighted toward the life sciences (e.g., the U.S.) may receive proportionately more citations than a country whose portfolio is more heavily weighted toward engineering or mathematics.
[41] The reader is reminded that articles in this section are counted by the year they entered the database, not by year of publication. Therefore article counts, and percentages based on them, are different from the data presented earlier in this section.
[42] Some part of this percentage decrease may reflect the increase in Chinese journals in the SCI and SSCI databases used in this chapter. Since more Chinese authors in these journals are available to cite their Chinese coauthors, international citations to Chinese-authored articles is declining as a share of total citations. However, accounting for the "nationality" of a journal is not straightforward, and the data file used by NSF excludes journals that are primarily of regional interest. NSF's count of "Chinese" journals shows an increase of 75% over the past decade, compared to an increase of 334% for Chinese-authored articles.
[43] Percentiles are specified percentages below which the remainder of the articles falls. For example, the 99th percentile identifies the number of citations 99% of the articles failed to receive. For example, across all fields of science, 99% of articles from 2005 to 2007 failed to receive at least 21 citations in 2009. Matching numbers of citations with a citation percentile is not precise because all articles with a specified number of citations must be counted the same. Therefore, the citation percentiles discussed in this section and used in appendix tables 5-44 and 5-45 have all been counted conservatively, and the identified percentile is in every case higher than specified, (i.e., the 99th percentile is always greater than 99%, the 95th percentile is always greater than 95%, and so forth). Actual citations/percentiles per field vary widely because counts were cut off to remain within the identified percentile. For example, using this method of counting, the 75th percentile for engineering contained articles with three to four citations in 2005 through 2007, whereas the 75th percentile for astronomy contained articles with 6 to 10 citations.
[44] For an overview of these developments in the 20th century, see Mowery (2002).
[45] Sharp changes in the number of patents granted are related to the speed of processing at United States Patent and Trademark Office.
[46] The institutions listed in appendix table 5-46 are slightly different from those listed in past volumes, and data for individual institutions may be different. In appendix table 5-46, an institution is credited with a patent even if it is not the first assignee, and therefore some patents may be double counted. Several university systems are counted as one institution, and medical schools may be counted with their home institution. Universities also vary in how they assign patents (e.g., to boards of regents, individual campuses, or entities with or without affiliation with the university).
[47] The patent counts reported by Association of University Technology Managers respondents in figure 5-32 and appendix table 5-48 cannot be compared with the patent counts developed from USPTO data as in appendix tables 5-46 and 5-47.
[48] Patent-based data must be interpreted with caution. Year-to-year changes in the data may reflect changes in USPTO processing times (so-called "patent pendency" rates). Likewise, industries and companies have different tactics and strategies for pursuing patents, and these may also change over time.

Patent citations to S&E research discussed in this section are limited to the citations found on the cover pages of successful patent applications. These citations are entered by the patent examiner, and may or may not reflect citations given by the applicant in the body of the application. Patent cover pages also contain references to scientific and technical materials not contained in the article data used in this chapter (e.g., other patents, conference proceedings, industry standards, etc.). Analyses of the data referred to in this section found that nonjournal references on patent cover pages accounted for 19% of total references in 2008. The journals/articles in the SCI/SSCI database used in this chapter—a set of relatively high-impact journals—accounted for 83% of the journal references, or 67% of the total science references, on the patent covers.
[49] Pilot Program for Green Technologies Including Greenhouse Gas Reduction, 74 Fed. Reg. 64,666 (USPTO, December 8, 2009).
[50] Due to data limitations, this discussion is limited to the following: patent data are patent awards made by the USPTO to all assignees, not just U.S. assignees. S&E publication data are for all publications in all U.S. sectors and all country authors.
[51] Compare with Organisation for Economic Co-operation and Development, 2010, p.36.