Gu, Z.

We have introduced a new metric, \"citation enrichment\", to measure the country-to-country influence using citation data. This metric evaluates the preference of a country to cite the other country compared to a random citation process. We applied the citation enrichment method on over 14 million publications in the life science and biomedical fields and we have the following findings: 1) The globe is split into two separated worlds where developed western countries exhibit an overall mutual negative influence on the remaining of the world. 2) Within each world, countries form clusters based on their mutual influences and the classification fits perfectly to their geographical and cultural proximity. 3) The two worlds exhibit distinct dynamics on the citation balance among countries. We have constructed a comprehensive world map of scientific influence which greatly enhances the deep understanding of international exchange of scientific knowledge. The citation enrichment metric is developed under a well-defined statistical framework and it can be extended to a general and powerful tool for research in bibliometrics and related fields.