  This article seeks to provide accurate estimates of the causal effect of
exposure to toxic language on player engagement and the proliferation of toxic
language. To this end, we analyze proprietary data from the first-person action
video game Call of Duty: Modern Warfare III, published by Activision. To
overcome causal identification problems, we implement an instrumental variables
estimation strategy. Our findings confirm that exposure to toxic language
significantly affects player engagement and the probability that players use
similar language. Accordingly, video game publishers have a vested interest in
addressing toxic language. Further, we demonstrate that this effect varies
significantly depending on whether toxic language originates from opponents or
teammates, whether it originates from teammates in the same party or a
different party, and the match's outcome. This has meaningful implications
regarding how resources for addressing toxicity should be allocated.
