A Spatial Theory of Media Slant and Voter Choice

Abstract

We develop a theory of media slant as a systematic filtering of political news that reduces multidimensional politics to the one-dimensional space perceived by voters. Economic and political choices are interdependent in our theory: expected electoral results influence economic choices, and economic choices in turn influence voting behavior. In a two-candidate election, we show that media favoring the frontrunner will focus on issues unlikely to deliver a surprise, while media favoring the underdog will gamble for resurrection. We characterize the socially optimal slant and show it coincides with the one favored by the underdog under a variety of circumstances. Balanced media, giving each issue equal coverage, may be worse for voters than partisan media. 1. "The space in which political parties compete can be of highly variable structure. Just as the parties may be perceived and evaluated on several dimensions, so the dimensions that are salient to 4. As discussed later on, this result can be nicely contrasted with the "issue ownership" view of Petrocik (1996) and others.

Political disagreement and information in elections

“…Therefore, (17) implies that the sender's expected utility depends on posterior beliefs only through the posterior expectation of the state. Furthermore, function K is assumed to be twice differentiable, with a strictly positive derivative…”

Bayesian persuasion with heterogeneous priors

“…Lacking a rational basis for selecting a prior, the assumption that individuals should, nevertheless, all agree on one may seem unfounded. 11 Our assumption of a commonly understood experiment is similar to the notion of "concordant beliefs"…”

“…We first show that if some ε satisfies (41), then the value of information control is positive. Consider V S defined in (11), which in this case can be written as…”

Persuading Skeptics and Reaffirming Believers

“…This class of equilibria is non-empty: an equilibrium in which whenever the receiver is indi↵erent between actions he selects an action that maximizes the sender's expected utility, as a function of posterior beliefs only, is a (sender-preferred) language-invariant equilibrium for which v is upper semicontinous. 9 Given a language-invariant equilibrium that induces v, the sender's 9 As noted in KG, this follows from Berge's maximum theorem. Upper-semicontinuity will prove convenient when establishing the existence of an optimal signal.…”

“…⌘i⌘ belongs to the convex hull of the graph of the function V S given by (9). Moreover, for any point (p S , w) in the convex hull of the graph of V S there exists a signal that induces (p S , w) over posteriors of the sender, and such that w = E…”