Transmitting Terror: Radio and Repression in Stalin’s Soviet Union

Mass media often persuades; it can also expand the machinery of repression. We study radio network expansion and political persecution in Stalin's Soviet Union, in the decades leading up to the 'Great Terror' of 1937-38. Greater radio coverage systematically intensified political repression: a one-standard-deviation increase in signal strength is associated with about 40 percent more arrests and a 20 percent higher likelihood that an arrested individual is executed, with effects that grew over time. For identification, we exploit newly digitized county-level panel data for 1920–1940 and variation in longwave radio signal strength driven by ground-conductivity differences along propagation paths. Additional repression was disproportionately 'misdirected'. Post-Stalin rehabilitation records show that high-signal areas produced substantially more sentences later reversed. Within the security apparatus itself, stronger radio reception reduced recruitment into the NKVD. It also increased the probability that incumbent officers were purged or demoted, consistent with tighter monitoring and escalating internal risk. Mass communication was not only persuasive; it operated as an input into coercive state capacity by lowering the coordination and monitoring costs of repression.