Andrea Prat, Tommaso Valletti, 26 July 2018

Competition authorities struggle to evaluate the effect of mergers between social media platforms when prices are zero and standard tools like cross-price elasticities are of little use. This column argues that social media platforms are 'attention brokers' that help incumbents maintain market power in other industries by restricting producers’ targeted access to individual consumers. User overlap is more important as a predictor of competition problems than traditional aggregate usage shares. 

Yuriy Gorodnichenko, Tho Pham, Oleksandr Talavera, 02 June 2018

The rise of social media has profoundly affected how people acquire and process information. Using Twitter data on the Brexit referendum and the 2016 US presidential election, this column studies how social media bots shape public opinion and voting outcomes. Bots have a tangible effect on the tweeting activity of humans, but the degree of their influence depends on whether they provide information consistent with humans’ priors. The findings suggest that effect of bots was likely marginal, but possibly large enough to affect voting outcomes in the two elections.

Vahid Gholampour, Eric van Wincoop, 15 May 2017

Large numbers of traders share their thoughts about the euro-dollar exchange rate on Twitter. By identifying and classifying opinionated tweets, and constructing a daily measure of sentiment, this column shows that a trading strategy that takes long or short positions based on the forecasts of high-follower accounts provides a Sharpe ratio significantly above that of the carry trade. The methodology could easily be applied to other currencies or portfolios of currencies, as well as other financial markets such as the stock market.

Maria Petrova, Ananya Sen, Pinar Yildirim, 28 February 2017

New communication technologies change the way people become informed and stay connected, and can also change voter behaviour. This column uses a dataset covering 1,814 candidates for the US Senate with Twitter accounts to analyse how using a new social media technology can overcome the barriers of communicating with voters. Candidates receive more campaign donations after they join Twitter, but adopting the technology seems to help only new, inexperienced politicians. This suggests that new technologies can ease entry to politics for new candidates and promote political competition.

Events

CEPR Policy Research