Understanding the Changing Structure of Scientific Inquiry

The fall of the Iron Curtain led to an influx of new mathematical ideas into western science. We show that research teams grew disproportionately in size in subfields of mathematics in which the Soviets were strongest. This is consistent with the knowledge burden hypothesis that an outward shift in the knowledge frontier increases the returns to collaboration. We also report additional evidence consistent with this interpretation: (i) The effect is present in countries outside the United States and is not correlated with the local population of Soviet scholars, (ii) Researchers in Soviet-rich subfields disproportionately increased their level of specialization.