From Friends to Foes: Identity and Team Performance

Abstract: This project studies the consequences of an international political conflict for composition and performance of teams on GitHub, the world's largest open-source platform. I exploit the unexpected conflict between Russia and Ukraine following the annexation of Crimea in March 2014 and analyse the impact of this conflict on the online collaboration between Ukrainian and Russian programmers. Using microdata from GitHub, I show that the conflict exerted a strong negative effect on Ukrainian-Russian collaboration and provide evidence for the causal role of national identity. I then discuss potential channels, through which an identity shock could affect performance of online teams: first, by hindering communication within a diverse team and second, by changing the taste of some team members for projects initiated by a "hostile" social group.