Do search engines increase concentration in media markets?

Search engines are one of the main channels to access news content of traditional newspapers. In the European Union, organic search traffic from Google accounts for 35% of news outlets’ visits. Yet, the effects of Google Search on market competition and information diversity are ambiguous, as the firm indexes news outlets considering both domain authority and information accuracy. Using detailed daily data traffic for 606 news outlets from 15 European countries, we assess the effect of Google Search’s indexation on search visits. Our identification strategy exploits nine core algorithm updates rolled out by Google between 2018 and 2020 in order to achieve exogenous variation in news outlets’ indexation. Several conclusions follow from our estimations. First, Google core updates overall reduce the number of keywords that news outlets have in top positions in search results. Second, keywords ranked in top search position have a positive effect on news outlets’ visits. Third, our results are robust when we focus the analysis on different types of news outlets, but are less conclusive when we consider national markets separately. Our paper also analyzes the effects of Google core updates on media market concentration. We find that the three “big” core updates identified in this period reduced market concentration by 1%, but this effect was mostly compensated by the rest of the updates