What Drives Media Slant? Evidence from U.S. Daily Newspapers

We construct a new index of media slant that measures whether a news outlet.s language is more similar to that of a congressional Republican or Democrat. We apply the measure to study the market forces that determine political con- tent in the news. We estimate a model of newspaper demand that incorporates slant explicitly, estimate the slant that would be chosen if newspapers independently maximized their own profits, and compare these ideal points with .rms. actual choices. Our analysis confirms an economically significant demand for news slanted toward one's own political ideology. Firms respond strongly to consumer preferences, which account for roughly 20 percent of the variation in measured slant in our sample. By contrast, the identity of a newspaper's owner explains far less of the variation in slant. We also present evidence on the role of pressure from incumbent politicians, tastes of reporters, and newspaper competition in determining slant.

Does Television Rot Your Brain? New Evidence from the Coleman Study

We use heterogeneity in the timing of television's introduction to different local markets to identify the effect of preschool television exposure on standardized test scores later in life. Our preferred point estimate indicates that an additional year of preschool television exposure raises average test scores by about .02 standard deviations. We are able to reject negative effects larger than about .03 standard deviations per year of television exposure. For reading and general knowledge scores, the positive effects we find are marginally statistically significant, and these effects are largest for children from households where English is not the primary language, for children whose mothers have less than a high school education, and for non-white children. To capture more general effects on human capital, we also study the effect of childhood television exposure on school completion and subsequent labor market earnings, and again find no evidence of a negative effect.

Media, Education, and anti-Americanism in the Muslim World

Recent surveys in the United States and the Muslim world show widespread misinformation about the events of September 11, 2001. Using data from 9 predominantly Muslim countries, we study how such beliefs depend on exposure to news media and levels of education. Standard economic theory would predict that increased access to information should cause beliefs to converge. More recent models of biased belief formation suggest that this result might hinge critically on who is providing the information. Consistent with the latter, we find that overall intensity of media use and level of education have at best a weak correlation with beliefs, while particular information sources have strong and divergent effects. Compared to those with little media exposure or schooling, individuals watching Arab news channels or educated in schools with little Western influence are less likely to agree that the September 11 attacks were carried out by Arab terrorists. Those exposed to media or education from Western sources are more likely to agree. Belief that the attacks were morally justified and general attitudes toward the US are also strongly correlated with source of information. These findings survive controls for demographic characteristics and are robust to identifying media effects using cross-country variation in language.persuasion, media, bias, terrorism

Algorithmic Bayesian Persuasion

Persuasion, defined as the act of exploiting an informational advantage in order to effect the decisions of others, is ubiquitous. Indeed, persuasive communication has been estimated to account for almost a third of all economic activity in the US. This paper examines persuasion through a computational lens, focusing on what is perhaps the most basic and fundamental model in this space: the celebrated Bayesian persuasion model of Kamenica and Gentzkow. Here there are two players, a sender and a receiver. The receiver must take one of a number of actions with a-priori unknown payoff, and the sender has access to additional information regarding the payoffs. The sender can commit to revealing a noisy signal regarding the realization of the payoffs of various actions, and would like to do so as to maximize her own payoff assuming a perfectly rational receiver. We examine the sender's optimization task in three of the most natural input models for this problem, and essentially pin down its computational complexity in each. When the payoff distributions of the different actions are i.i.d. and given explicitly, we exhibit a polynomial-time (exact) algorithm, and a "simple" $(1-1/e)$-approximation algorithm. Our optimal scheme for the i.i.d. setting involves an analogy to auction theory, and makes use of Border's characterization of the space of reduced-forms for single-item auctions. When action payoffs are independent but non-identical with marginal distributions given explicitly, we show that it is #P-hard to compute the optimal expected sender utility. Finally, we consider a general (possibly correlated) joint distribution of action payoffs presented by a black box sampling oracle, and exhibit a fully polynomial-time approximation scheme (FPTAS) with a bi-criteria guarantee. We show that this result is the best possible in the black-box model for information-theoretic reasons

The Effect of Newspaper Entry and Exit on Electoral Politics

We use new data on entries and exits of US daily newspapers from 1869 to 2004 to estimate effects on political participation, party vote shares, and electoral competitiveness. Our identification strategy exploits the precise timing of these events and allows for the possibility of confounding trends. We find that newspapers have a robust positive effect on political participation, with one additional newspaper increasing both presidential and congressional turnout by approximately 0.3 percentage points. Newspaper competition is not a key driver of turnout: our effect is driven mainly by the first newspaper in a market, and the effect of a second or third paper is significantly smaller. The effect on presidential turnout diminishes after the introduction of radio and television, while the estimated effect on congressional turnout remains similar up to recent years. We find no evidence that partisan newspapers affect party vote shares, with confidence intervals that rule out even moderate-sized effects. We find no clear evidence that newspapers systematically help or hurt incumbents.

Do Newspapers Serve the State? Incumbent Party Influence on the US Press, 1869-1928

Using data from 1869 to 1928, we estimate the effect of party control of state governments on the entry, exit, circulation, prices, number of pages, and content of Republican and Democratic daily newspapers. We exploit changes over time in party control of the governorship and state legislatures in a differences-in-differences design. We exploit close gubernatorial elections and state legislatures with small majorities in a parallel regression-discontinuity design. Neither method reveals evidence that the party in power affects the partisan composition of the press. Our confidence intervals rule out modest effects, and we find little evidence of incumbent party influence even in times and places with high political stakes or low commercial stakes. The one exception is the Reconstruction South, an episode that we discuss in detail

Cross-Checking the Media

A characteristic of the news market is that consumers often cross-check information, i.e. observe several news outlets. At the same time, data on political media suggest that more partisan consumers are more likely to cross-check. We explore these phenomena by building a model of horizontal competition in newspaper endorsements. Without cross-checking, outlets are unbiased and minimally differentiated. When cross-checking is allowed, we show that cross-checkers are indeed more partisan than those who only acquire one report. Furthermore, cross-checking induces outlets to differentiate, and the degree of differentiation is increasing in the dispersion of consumer beliefs. Differentiation is detrimental to consumer welfare, and a single monopoly outlet may provide higher consumer welfare than a competitive duopoly