Description:

Caterina Chiopris (Columbia): The Diffusion of Ideas 

Abstract: The diffusion of innovation and new ideas is fundamental for economic growth, cultural shifts, and institutional change. How are new ideas created, and how do they diffuse? Specifically, how do spatial connections affect the generation and diffusion of ideas? Intuitively, a denser network should increase the number of novel ideas and augment their diffusion. I study knowledge production in Germany in the 19th century, relying on several novel large-scale datasets, including the universe of bibliographic records and detailed railway statistics. New ideas are measured as novel concepts, new combinations of existing ideas, as well as new topics and fields. I show that the railroad network increased the creation of new ideas, but decreased their average diffusion. This was a by-product of specialization: with a more integrated knowledge market, groups of scholars started focusing on narrower topics and were more likely to co-locate with similar professionals; they adopted ideas from similar groups, but became disconnected from dissimilar ones. These patterns paved the way for modern knowledge production; qualitative evidence suggests that this has important consequences not only for scientific breakthroughs, but also for state institutions, bureaucratic specialization and the exhaustiveness of legislation.