Stars Scientists and Firm Entries in the World


Number of high-tech firm entries in the geographic area in a given year.
Number of highly cited scientists active in the geographic area in a given year.


  1. The maps have been produced using the data compiled for the article: Lynne G. Zucker and Michael R. Darby, "Movement of Star Scientists and Engineers and high-tech firm entry," April 2006, NBER Working Paper 12172, to be presented at the CAFE Conference, September 28-30, 2006,at the Institut fur Arbeitsmarkt-und Berufsforschung, Nürnberg, Germany.
  2. The geographic regions used for grouping are the 25 top science and engineering countries defined as all countries that had one or more authors on at least 0.5 percent of all ISI articles or that had one or more inventors on at least 0.1 percent of all US patents granted., or both. The 25 countries are (in order of total number of articles and patents): United States, Japan, Germany, United Kingdom, France, Canada, South Korea, Switzerland, Taiwan, Italy, Sweden, Netherlands, Finland, Australia, Israel, Belgium, Denmark, Austria, Norway, Spain, USSR/Russia, India, China, Poland and Brazil. Overall, these 25 countries account for 92.8 percent of all ISI articles and 99.3 percent of all U.S. patents.
  3. A firm entry is the first appearance in a country of a publication with an author affiliated to that firm or patent that is granted by USPTO with the firm listed as assignee at the time the patent is issued. Location in a country is determined by the address(es) of the firm appearing in the ISI article file or the address(es) of the inventor(s) in the case of a patent.
  4. The firm entries and highly-cited scientists are originally grouped into 6 major science and engineering categories based on the ISI articles and USPTO patents. These categories are Biology/Medicine/Chemistry, Computer/Information Processing/Multimedia, Integrated Circuit/Semiconductor/Superconductor, Nanotechnology, Other Engineering and Other Science. For the purposes of these maps, the fields apart from nanotechnology are combined into "non-nano."
  5. Locations and scientific fields of highly cited scientists have been traced using their academic publications. Each scientist, each year was assigned to the scientific field he’s most active in (determined by the fields they publish their articles in). They are also assigned to the geographic area they are most active in, determined by the location of the affiliations they list. (For more detailed discussion, please see Zucker and Darby, 2006.)
  6. The maps provides visual evidence for the results established in Zucker and Darby (2006). The high correlation between the highly cited scientists and high-tech firm entry can be seen in both nanotech and other scientific areas. In terms of labor mobility, the graphs suggest that the stars show a clear tendency toward concentration by area. This can be interpreted as stars being likely to move where other stars are.
  7. Comparing nanotechnology with non-nano, the progression of graphs with time clearly show the trend of nano expanding at a much higher rate than non-nano.
  8. Comparisons within different US regions of nano stars and firm entries with those of non-nano are provided in