Interview with Matthew Gentzkow

Stanford economist on TV & children, TV & voting, politics & persuasion, and the vibrant future of media economics

Before Matthew Gentzkow entered the field, the economics of media was largely uncharted territory. Today, media economics is flourishing thanks largely to him and his co-authors—particularly Jesse Shapiro, a frequent collaborator

.. With unique insights, innovative technique, methodological rigor and massive databases he often creates for an express purpose, Gentzkow has answered questions about television, newspapers, product branding, competition, persuasion and politics that many scholars had asked but no one had answered convincingly.

.. Due to this work, we now know that newspaper media slant is driven mostly by the preferences of readers, not newspaper owners. And by examining browser data, he discovered that people don’t largely live in internet “echo chambers”—that is, they don’t exclusively visit sites that align with their political bent. Product brand preferences, he found, are established early in life and endure long after exposure to essentially identical, less expensive alternatives. These and dozens of other economic mysteries have yielded to his curiosity, insight and skill.

.. For the earlier paper, I developed a strategy of using the rollout of TV across different markets. In the United States, television was introduced to different cities in different years, basically because of idiosyncrasies in the regulatory process.

.. it’s hard to think of anything that determines how much TV kids watch that isn’t correlated with their parents, their environment, their intelligence. So, looking at a kid who watches four hours of TV a day and another kid whose parents don’t let him watch any TV—it’s hard to learn much from that.

.. you can’t talk about the effect of TV without thinking about what it’s crowding out. TV viewing is shifting time around.

.. it’s easy to imagine that for some kids, watching television is a much richer source of input than a lot of what it might be crowding out. TV has lots of language; it exposes them to lots of different people and ideas.

.. It’s also easy to imagine kids for whom it could be a lot worse than whatever else they would have been doing. Educated, wealthy parents or parents with a lot of time to invest in their kids might be taking them to museums and doing math problems with them and so forth. I think part of the reason so many people writing about this assume TV is bad is that they themselves are in the latter group.

.. Although there was some political content on TV, it was much smaller, and particularly much smaller for local or state level politics, which obviously the national TV networks are not going to cover.

So, we see that when television is introduced, indeed, voter turnout starts to decline. We can use this variation across different places and see that that sharp drop in voter turnout coincides with the timing of when TV came in.

.. the Internet as well, have increased particularly in national news and political coverage, these forces are pushing people toward paying less attention to local politics, local issues, local communities, and they’re being pulled toward either more entertainment options or more attention to national-level politics.

.. To try to separate those things, it seemed like you could learn a lot from looking at people who move from a place where one brand is popular to a place where another is popular.

.. another co-author of theirs, had written a really important paper in the Journal of Political Economya couple of years earlier that documented huge differences across U.S. cities in which brands are popular. They showed that that actually is correlated with the timing of which brands were introduced first in those cities, even though all of those introductions happened, for the most part, 50 or 100 years ago and few people remember a time when you couldn’t buy both.

.. The question then is, if somebody was born in a place where Coke is popular and moved to a place where Pepsi is popular, where does that person’s consumption fall in between those products, and how does that depend on how long they’ve been in one place or the other?

.. Then imagine somebody moving from a place where there’s low spending on health care to a place with high spending, and you see how things change

.. if I’m somebody who believes very strongly that global warming is a hoax or that the evidence for it is weak, and a lot of people I’ve talked to believe that global warming has been exaggerated, then if I see news outlets that are arguing otherwise, I’m going to trust them less. And if I see news outlets that are skeptical about global warming, I’m going to trust them more.

.. suppose the reason people in Minneapolis seem to have really low spending is, in part, that they are just healthy—they have better diets, better exercise, lower smoking rates or other, less-observable reasons why their health status is better. If they move to Texas, they’re going to carry that with them, and it’s not going to diminish or deteriorate as they live in Texas. It’s something innate or pretty fixed.

.. One of the things we found in looking at newspapers is that their political slant or political content seems to be driven very strongly by demand from their readers, the fact that people in conservative places want to hear conservative stuff and the converse for liberals. And that slant is basically uncorrelated with anything about their owners, the ownership of the paper.

.. It could be entirely consistent with those results that in other countries, in other contexts, it may well differ. Does Silvio Berlusconi influence the media in Italy? A lot of evidence suggests yes. Does control by the government of Russia affect the content of the media in Russia? Or even if we were to look at national cable outlets in the U.S., would we be confident that ownership doesn’t matter? I think that’s a pretty big leap; you need to be careful.

.. Rather, I’m watching it because I genuinely think it’s the most accurate source of information there is.

.. it’s very well documented historically that up until the late 19th century, newspapers were to a substantial degree funded by and explicitly controlled by political parties in this country.

.. As costs of printing newspapers fell dramatically, as the potential profits you could earn from selling newspapers increased, the incentive to instead focus on what consumers want got really big. So you saw a shift.

.. The data available to study media are typically very good almost everywhere. Media are funded by advertising, and advertisers need information about who’s watching and reading and what people are doing. So, no matter where you go in the world, people are keeping track of what are the TV stations and where are they available, the newspapers and their circulations, and just generally, what are people watching and how many people are watching different things.

.. It’s true that social media is significantly segregated; what people click on and see and share tends to be close to their own ideology. We know that social networks are very segregated ideologically, and social media reflects that. It just remains true that the share of news that people are getting through social media is still, on average, a small share of the total.