Scientific knowledge dynamics and relatedness in biotech cities

This paper investigates the impact of scientific relatedness on knowledge dynamics in biotech at the city level during the period 1989-2008. We assess the extent to which the emergence of new research topics and the disappearance of existing topics in cities are dependent on their degree of scientific relatedness with existing topics in those cities. We make use of the rise and fall of title words in scientific publications in biotech to identify major cognitive developments within the field. We determined the degree of relatedness between 1028 scientific topics in biotech by means of co-occurrence of pairs of topics in journal articles. We combined this relatedness indicator between topics in biotech with the scientific portfolio of cities (i.e. the topics on which they published previously) to determine how cognitively close a potentially new topic (or an existing topic) is to the scientific portfolio of a city. We analyzed knowledge dynamics at the city level by looking at the entry and exit of topics in the scientific portfolio of 276 cities in the world. We found strong and robust evidence that new scientific topics in biotech tend to emerge systematically in cities where scientifically related topics already exist, while existing scientific topics had a higher probability to disappear from a city when these were weakly related to the scientific portfolio of the city. (C) 2013 Elsevier B.V. All rights reserved.