NATIONAL SCIENCE FOUNDATION
Directorate for Social, Behavioral
and Economic Sciences
NSF 99-350 June 18, 1999
by Lawrence M. Rausch
International Patenting Trends in Advanced Materials: Ceramics
Japan and the United States lead all other nations in the formation of international patent families involving ceramics technology.
Japan produced the greatest number of international patent families in this technology area, but the United States had the highest number of highly cited ceramics inventions.
This report is the third in a three-part series that examines America�s technological position vis-�-vis that of five other countries�Japan, Germany, France, the United Kingdom, and South Korea�in technical areas likely to be important to future economic competitiveness. The areas examined are advanced manufacturing, biotechnology, and advanced materials; the indicator used to determine a country�s relative strength and interest in these areas is international patent activity. To facilitate patent search and analysis, the three broad areas were each represented by a narrower subfield. This report examines advanced ceramic technologies as a proxy for advanced materials.
International Patenting Activity
Japan and the United States lead all other nations in the formation of international patent families involving advanced ceramics technology. Together they accounted for more than 70 percent of the total formed in the 5-year period examined. Japan held 39 percent of the total families formed during this period (381 international families); the United States held 32 percent (310 international families).
Highly Cited Advanced Ceramics Inventions
Of the 968 international patent families formed by the six countries during the 1990-94 period, 23 were considered highly cited inventions. Japan generated the greatest number of international patent families in this technology area during the period, but the United States had the greatest number of highly cited inventions with 15 (or 65 percent of all highly cited international patent families). Japan was second with 4. When each country�s number of highly cited international patent families is adjusted to account for its overall volume of international patenting in this technology (citation ratio), the United States again leads all six nations. The United States had a citation ratio of 2.0�that is, U.S. inventors� share of highly cited international patent families was twice its share of the total international patent families formed during this period. Japan�s citation ratio, 0.4, suggests that the four highly cited international families it produced during this period were below the level expected given the total number of international patent families the country generated. The United Kingdom had only two highly cited international families, but exceeded expectations in this indicator with a citation ratio of 1.8 (table 1). France and Germany each had one highly cited international patent family; this again was below expectations given their respective shares of total international patent families in this technology.
Average International Patent Family Size
Based on an adjusted average international family size, the advanced ceramics inventions with the highest perceived commercial potential, on average, were produced in France; these were closely followed by those produced in the United States (table 2). The United States also had the second largest number of international patent families for the period examined. Japan, the most prolific inventor of advanced ceramics technologies during the 1990-94 period, trailed the United States and the large European nations in terms of average commercial potential for each invention. South Korean inventions showed the lowest commercial value based on this indicator: the country was at a relative disadvantage due to its small home market. Conversely, since most inventions are first patented in the country in which the inventor resides, U.S. inventions have an edge in the calculation for this indicator because of the large size of the U.S. economy. Using international patent families as the unit of comparison�as is done here�reduces this bias. Because of its market size, the United States attracts most commercially important inventions and is likely to be a member of many of the international patent families included in this indicator.
Summary of U.S. Position
Mogee Research & Analysis Associates. 1997. Comparing Assessments of National Position in Key Science & Technology Fields. Report prepared under National Science Foundation, Small Grants for Exploratory Research (SGER) Grant No. SRS-9618668. Washington, DC.
���. 1997. Science & Technology Shaping the Twenty-First Century. Washington, DC: Executive Office of the President.
This Issue Brief was prepared by:
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 These data were developed under contract for the National Science Foundation by Mogee Research & Analysis Associates and cover the period 1990-94; they were extracted from the Derwent World Patents Index Database published by Derwent Publications, Ltd. The technology areas selected for this study met several criteria:
- Each technology appeared on the lists of �critical� technologies deemed important to future U.S. economic competitiveness or national security (see Mogee 1991; OSTP 1995; and Popper, Wagner, and Larson 1998).
- Each technology could be characterized by the output of patentable products or processes.
- Each technology could be defined sufficiently to permit construction of accurate patent search strategies.
- Each technology yielded a sufficient population for statistical analysis.
 The declining number of international patent families formed during the period does not necessarily indicate any drop in inventive activity. It may only reflect the younger age of these inventions.
 The data used here include all patent families with priority application dates from 1990-94 with four or more citations. The citation counts are those placed on European Patent Office (EPO) patents by EPO examiners, as the EPO citations are believed to be a less biased and broader source of citation than those of the U.S. Patent and Trademark Office. See Claus and Higham (1982). To adjust for the advantage countries with large numbers of international inventions would have on this indicator, a country�s share of highly cited patents is divided by its share of total patent families.
 The market-size indicator is a ratio of a country�s GDP to that of the United States valued in purchasing power parities at current U.S. dollars.