Working Paper（22-007E）The Role of Face-to-face Contact on Innovation: Evidence from the Spanish Flu

is persistency suggests that the decline of innovation activities in collaboration intensive technologies caused by the persistent decline of human interactions due to the death of the inventors by the pandemic. [...] Hence, instead of using a binary variable on the treatment group or the control group, we conduct the same DID exercise using the share of co-invented patent in the patent applications before the pandemic as the treatment variable. [...] ese results suggest that the decline in the number of patents in collaboration intensive technology is driven by the decline in the entries of new inventors, not by the decline in inventions by incumbent inventors. [...] Even though we control for the number of total patents on the rst year of invention, the number of solo-invented patents are signicantly fewer than the rest of the inventor’s career. [...] Contrasting the solo-invented patents on the rst year of invention, the number of co-invented patents are signicantly more than the rest of the inventor’s career.