Marcel Garz

We’re happy to announce that the next media bias workshop will take place on March 31 and April 1, 2022, at Berlin Social Science Center. Gregory Crawford and Alios Stutzer will deliver the keynote speeches. The call for papers can be downloaded here.

I joined a group of researchers that investigates media bias from a highly interdisciplinary perspective. The media bias group develops systems and large-scale datasets to automatically detect biased or unbalanced coverage, using methods from disciplines such as computer science, linguistics, psychology, and economics. The groups also devises new ways to visualize data, in an effort to better understand what types of bias appear in which context.

Content selection algorithms of social media platforms have a reputation for creating filter bubbles, where users are primarily exposed to politically like-minded information. In a new paper, Ferenc Szucs and I take a supply-side perspective: We investigate the role of Facebook’s news feed algorithm for content created by media companies. Specifically, we evaluate the effects of two major changes in the algorithm on the political bias of stories posted by German news outlets. In December 2013 and August 2014, Facebook publicly announced measures designed to boost the dissemination of quality news stories. Using a differences-in-differences strategy, our results indicate greater levels of within-outlet ideological diversity of news posted on Facebook after the second algorithm update, relative to the print coverage. The effect can be explained largely explained by a shift of the outlets towards more news and less trivia, which reduced deviations from the distribution of ideologically relevant expressions used in their print editions.

In a recent study, Greg Martin and I investigate how news about the economy influences voting decisions. We isolate the effect of the information environment from the effect of change in the underlying economic conditions themselves, by taking advantage of left-digit bias. We show that unemployment figures crossing a round-number “milestone” causes a discontinuous increase in the amount of media coverage devoted to unemployment conditions, and use this discontinuity to estimate the effect of attention to unemployment news on voting, holding constant the actual economic conditions on the ground. Milestone effects on incumbent US Governor vote shares are large and notably asymmetric: bad milestone events hurt roughly twice as much as good milestone events help.

The Swedish Competition Authority has approved funding in the amount of approx. 180,000 euro for a project of mine entitled “Media Competition and Media Slant in Swedish Newspapers” (with Jonna Rickardsson). The project investigates how competition in local media markets affects the diversity of opinions in newspaper coverage. Specially, we (1) construct an index of ideological slant, (2) investigate which motives of media owners drive the slant, and (3) estimate the causal effect of competition on slant. The results aim to inform the debate on media regulation, with a focus on press subsidies and the measurement of media concentration.

After a successful start of the series in June 2015, the fourth Economics of Media Bias Workshop will take place on February 21-22, 2019, in Berlin, Germany. Eliana La Ferrara (Bocconi University) will deliver the keynote speech. The workshop, which is organized by my colleagues and me, addresses the forms, causes, and consequences of media bias, especially in news markets. The program can be downloaded here.