Technological Breakthroughs, Entry, and the Direction of Scientific Progress: Evidence from CRISPR/Cas9

Understanding the direction of technical progress is a central issue for the study of innovation. In this paper, I examine how the introduction of a breakthrough research tool affects the trajectory of a scientific field through new entry and project selection. Specifically, I examine the impact of the genome editing system CRISPR/Cas9 (CRISPR), called the biggest game changer to hit biology since PCR (Ledford 2015). Introduced in 2012, CRISPR/Cas9 enables precise DNA editing and carries the potential to develop everything from blight resistant crops to targeted genetic drug therapies. Although biologically CRISPR/Cas9 provides more benefits to researchers working on mammalian organisms than to researchers working on bacterial organisms. I hypothesize that its impact on the direction of genetic engineering research depends on its relative value across animal models. To investigate CRISPR/Cas9\u27s impact, I use two novel datasets on genetic engineering research histories. The first comes from the biological resource center, Addgene, that identifies researcher experimentation with CRISPR/Cas9. The second uses publication histories for academics that eventually adopt CRISPR/Cas9. The Addgene data demonstrate that the introduction of CRISPR/Cas9 corresponded to an immediate increase in experiments with mammalian organisms relative to bacterial organisms. The publication data demonstrate that the shift towards mammalian genetic engineering research results neither (a) from an increase in the productivity of researchers who had previously worked on mammalian models nor (b) from incumbent bacterial authors switching their focus to mammalian research after the discovery. Instead, the data suggest that the shift towards mammalian genetic engineering research results from entry, i.e., from new authors attracted to the field. Given strong qualitative evidence that CRISPR/Cas9 increased mammalian researcher productivity, the lack of empirical support is surprising. Since CRISPR/Cas9 is recent, more data is needed before it is possible to see delayed effects. The paper lays the groundwork for subsequent research on the effect of new innovations on the rate and direction of scientific progress in this new and rapidly changing setting