American Scientist

Is the United States losing its world leadership in science and engineering? During the years 1993-1997, U.S. authors' publications amounted to 37.46 percent of the world total of research output; in 1997-2001, they represented 34.86 percent. The relative "impact" of U.S. publications has decreased proportionally. The U.S. share of the world's citations was 52.3 percent in 1993-1997, 49.43 percent in 1997-2001. Within the top 1 percent of highly cited publications, the U.S. percentage was 65.6 in 1993-1997, but 62.76 in 1997-2001. These data, presented in David A. King's 2004 article, "The Scientific Impact of Nations," Nature 430:311-316, were based on analysis of the Thomson ISI (formerly the Institute for Scientific Information) index of 8,000 journals published in 36 languages.

The numbers cited do not reflect a reduction in the number of U.S. publications (which increased from 1,248,733 to 1,265,808 between the two quinquennia) or in the impact of those highly cited (whose numbers increased from 22,710 to 23,723). The shrinking U.S. share is owed, rather, to increases achieved by other countries, notably the European Union. The number of publications (and percentage of the world's total) from EU15 countries—the 15 countries of the European Union before the 2004 accession—increased from 1,180,730 (35.42 percent) to 1,347,985 (37.12 percent) between the two quinquennia; the proportion of citations increased from 36.57 to 39.3 percent, and the proportion of publications among the 1 percent most cited increased from 32.85 to 37.3 percent. Japan's share of publications and citations increased proportionally between quinquennia about as much. Among other countries, proportional increases occurred in Brazil, China and India. China's proportion of the world's publications increased from 2.06 to 3.18 percent and citations from 0.95 to 1.56. These numbers' implied message is clear. The scientific productivity and impact of the United States are not keeping pace with the rest of the world's. It is a sobering situation, even if not yet an alarming one.

Among our immediate neighbors, Canada has experienced decreases proportionally similar to those of the U.S., declining from 5.05 to 4.58 percent of the world's publications and from 5.59 to 5.3 percent of the world's citations between 1993-1997 and 1997-2001. The numbers for Mexico are difficult to fathom and even more difficult to interpret, because a large proportion of high-impact publications by Mexican scientists are with U.S. co-authors. But various signs point toward substantial amelioration of Mexico's science enterprise in recent years. Among the 348 foreign members of the U.S. National Academy of Sciences, seven are from Mexico, more than from Brazil, China or India, which have much larger populations. Only ten countries in the world have more NAS foreign members than Mexico. Three of the Mexican scientists were elected in the last two years.

In November 2003, during Sigma Xi's Annual Meeting, officers of our Society met with leaders of Mexico's science establishment, including Jaime Parada Avila, the director of Consejo Nacional de Ciencia y Tecnología (CONACYT). The decision was taken to expand the number of Sigma Xi chapters in Mexico from only one currently in existence (in Monterrey) to ten. In response to an invitation letter from Sigma Xi's president, nearly two hundred Mexican scientists have applied for membership and been elected members in recent months. Leaders for various chapters have been identified, and petitions for the formation of new chapters are being prepared. It behooves all Sigma Xi members to invite their Mexican scientific collaborators to join our Society. Sigma Xi's officers, including myself, would appreciate this cooperation and any recommendations for this important step in enhancing the international significance of our Society.