| EDITOR'S NOTE: In 1991, the then-fledgling newsletter Science Watch analyzed the impact of research articles from hundreds of fields published and cited between 1981 and 1990 for 30 nations (2:1-2, Jan./Feb. 1991). In that study as well as the one reprinted here, the same five nations -- Switzerland, United States, Netherlands, Sweden, and Denmark -- placed in the top five. The current analysis ranks 30 nations according to their average citations per paper for articles published between 1992 and 1996 using the Philadelphia-based Insfitute for Scientific Information's (ISI's) National Science Indicators on Diskette. |
The Science Watch article analyzing the rankings (8:1-2, May/June, 1997) is reprinted here with the permission of the newsletter and lSI, its publisher. For more information on the citation databases and information discussed in the article, contact Christopher King, editor of Science Watch, ISI, 3501 Market St., Philadelphia, Pa. 19104; (800) 523-1850, Ext. 1341. Fax: (215) 387-1266. E-mail: firstname.lastname@example.org. World Wide Web http://www.isinet.com
European Union (EU) scientists now publish about as many papers as scientists from the United States, according to a new survey conducted by Science Watch. During the past 16 years, the EU's share of research papers increased from 30.5 percent to 36.2 percent, while the U.S. share fell from 40.5 percent to 36.5 percent. Also contributing to the decline in the U.S. world share is a dramatic increase in paper output by Asian and Latin American researchers. Clearly, as other nations have boosted their productivity-and at a rate faster than the U.S.-the U.S. slice of the pie has been eaten away bit by bit, particularly since 1991. As the graph at right shows, the EU increase and the U.S. decline have now reached a point of intersection, with the U.S. share of the world's total research papers currently exceeding Europe by only a few tenths of a percent.
To reveal these trends, Science Watch turned to the Institute for Scientific Information's (ISI's) National Science Indicators on Diskette, 1981-1996, a database containing publication and citation statistics in 102 subfields representing all areas of science, as well as the social sciences and selected fields in the arts and humanities. In addition to covering nearly 100 individual countries, the database contains aggregated data for three regions: the EU, Asia Pacific, and Latin America.
Source: ISI's National Science indicators on Diskette, 1981 - 1996
For each year from 1981 through 1996, Science Watch tracked each region's percentage of the total number of papers indexed in the ISI database. In 1981, the EU nations collectively produced 138,005 papers, or 30.5 percent of the 452,658 papers indexed in the ISI database that year. By 1996, the EU's share of the database had risen to 249,650 papers, or 36.2 percent of the world total of 690,215 papers. Of course, it is important to recognize that membership in the EU rose during the period surveyed, from 10 nations in 1981 to 12 in 1986 and, ultimately, to 15 in 1995.
In contrast to the EU, the U.S. produced 188,171 papers in 1981, or 40.5 percent of the world paper output as reflected in the ISI database. The U.S. figure in 1996 was 252,172 papers, or 36.5 percent of the world total. Although commanding smaller shares of the database, the Asia Pacific and Latin American regions both dramatically increased their overall percentages. The Asia Pacific group increased its percentage from its 1981 total of 58,006 papers, or 12.8 percent of the database, to 129,755 papers, or 18.8 percent, in 1996. Latin America's representation in the database grew from 5,822 papers, or 1.3 percent, in 1981 to 16,046 papers, or 2.3 percent, in 1996-nearly a doubling.
In discussing each of these aggregated regions, Science Watch is treating a group of many nations as if it were, in effect, one single nation. By this means, it is also possible to examine the fields in which the regions produced the greatest concentrations of papers, as well as the fields in which their papers had the greatest impact. Over the last five years, for example, the EU nations produced their highest concentration of papers in the field of rheumatology, collectively publishing 5,254 papers-55.5 percent of the world total of 9,461 papers from 1992 to 1996. Medical fields, in fact, dominate the fields in which the EU nations had the greatest share. Topping the list after rheumatology were gastroenterology (48.4 percent of papers in the field), dermatology (47.3 percent), endocrinology (45.9 percent), hematology (45.9 percent), and urology (44.6 percent).
The nations of the Asia Pacific region, meanwhile, concentrated most heavily in agricultural chemistry (37.9 percent of the papers in the field), metallurgy (32.9 percent), agriculture/agronomy (30.8 percent), materials science (28.5 percent), and applied physics/condensed matter/materials science (28.1 percent). In terms of relative impact, the Asia Pacific group bested the world citations-per-paper average in two main fields of science: pharmacology and toxicology (17 percent above the world-impact score) and geological/petrolum/mining engineering (6 percent above).
Latin America produced its highest percentages of papers in the fields of general biology (7.4 percent of the world total), agriculture/agronomy (7.4 percent), and space science (5.3 percent). As in the case of the Asia Pacific group, the citations-per-paper score of research from Latin America exceeded the world average in two fields: metallurgy (19 percent above the world mark) and pediatrics (3 percent above).
In addition to assessing these aggregated regions according to their respective portions of world output, Science Watch examined individual nations on the basis of their impact in all fields over the last five years. In the table at left, those nations that produced at least 5,000 papers during the five-year period are ranked according to their average citations per paper. Switzerland captured first place, followed by the U.S. and the Netherlands.
Six years ago Science Watch performed a similar analysis, ranking 30 nations according to the impact of papers published and cited between 1981 and 1990 (Science Watch, 2:1-2, January/February 1991). Switzerland topped that ranking as well. In fact, the same group of nations as last time occupy the top five spots, with only some minor shifts in position. The U.S. finished in the No. 2 spot in the current ranking, compared with its third-place showing in the 1991 survey. The Netherlands-fifth in the previous study-was No. 3 this time. Sweden, second-place finisher to Switzerland previously, wound up in fourth spot. Denmark, fourth in the previous survey, was virtually tied with Sweden, falling short of its 1991 spot by a mere thousandth of a percent.
The strong showing by the U.S. in the 1991 survey, as Science Watch noted at the time, seemed to belie the grim predictions that some observers were offering on the health of U.S. science. Six years later, although the U.S. has lost some of its world share of papers, the overall strength of U.S. science as measured by citation impact seems to be holding steady.