Valuing New Goods in a Model with Complementarities: Online Newspapers

Many important economic questions hinge on the extent to which new goods either crowd out or complement consumption of existing products. Recent methods for studying new goods are based on demand models that rule out complementarity by assumption, so their applicability to these questions has been limited. I develop a new model that relaxes this restriction, and use it to study the specific case of competition between print and online newspapers. Using new micro data from the Washington DC market, I show that the major print and online papers appear to be strong complements in the raw data, but that this is an artifact of unobserved consumer heterogeneity. I estimate that the online paper reduced print readership by 27,000 per day, at a cost of $5.5 million per year in lost print profits. I find that online news has provided substantial welfare benefits to consumers and that charging positive online prices is unlikely to substantially increase firm profits.

Bayesian Persuasion

When is it possible for one person to persuade another to change her action? We consider a symmetric information model where a sender chooses a signal to reveal to a receiver, who then takes a noncontractible action that affects the welfare of both players. We derive necessary and sufficient conditions for the existence of a signal that strictly benefits the sender. We characterize sender-optimal signals. We examine comparative statics with respect to the alignment of the sender's and the receiver's preferences. Finally, we apply our results to persuasion by litigators, lobbyists, and salespeople. (JEL D72, D82, D83, K40, M31)

Social Media and Fake News in the 2016 Election

Following the 2016 U.S. presidential election, many have expressed concern about the effects of false stories ("fake news"), circulated largely through social media. We discuss the economics of fake news and present new data on its consumption prior to the election. Drawing on web browsing data, archives of fact-checking websites, and results from a new online sur-vey, we find:(i) social media was an important but not dominant source of election news, with14 percent of Americans calling social media their "most important" source;(ii) of the known false news stories that appeared in the three months before the election, those favoring Trump were shared a total of 30 million times on Facebook, while those favoring Clinton were shared8 million times;(iii) the average American adult saw on the order of one or perhaps several fake news stories in the months around the election, with just over half of those who recalled seeing them believing them; and(iv) people are much more likely to believe stories that favor their preferred candidate, especially if they have ideologically segregated social media networks

Media Bias and Reputation

A Bayesian consumer who is uncertain about the quality of an information source will infer that the source is of higher quality when its reports conform to the consumer's prior expectations. We use this fact to build a model of media bias in which firms slant their reports toward the prior beliefs of their customers in order to build a reputation for quality. Bias emerges in our model even though it can make all market participants worse off. The model predicts that bias will be less severe when consumers receive independent evidence on the true state of the world, and that competition between independently owned news outlets can reduce bias. We present a variety of empirical evidence consistent with these predictions.

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

Competition in Persuasion

Does competition among persuaders increase the extent of information revealed? We study ex ante symmetric information games where a number of senders choose what information to gather and communicate to a receiver, who takes a non-contractible action that affects the welfare of all players. We characterize the information revealed in pure-strategy equilibria. We consider three ways of increasing competition among senders: (i) moving from collusive to non-cooperative play, (ii) introducing additional senders, and (iii) decreasing the alignment of senders' preferences. For each of these notions, we establish that increasing competition cannot decrease the amount of information revealed, and will in a certain sense tend to increase it.