Assumed Transmission in Political Science: A Call for Bringing Description Back In

News outlets cannot serve as reliable conveyors of social facts, nor do their audiences crave such content. Nonetheless, much political science scholarship assumes that objective information about social, political, and economic topics is routinely transmitted to the mass public through the news. This article addresses the problem of selection bias in news content and illustrates the problem with a content analytic study of New York Times coverage given to American war deaths in five major conflicts that occurred over the past century. We find that news coverage of war deaths is unrelated to how many American combatants have recently died. News coverage is more likely to mention war deaths when reporting combat operations and less likely to mention them when a war is going well. These findings underscore the need to document selection biases in information flows before theorizing about proximate causes underlying the relationships between political systems and public opinion.