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.

Ruben Enikolopov, Maria Petrova, Konstantin Sonin, 20 June 2016

In addition to the traditional mass media, social media has become a channel through which citizens can hold public officials and corporate leaders to account. But social media commentators can be vulnerable to manipulation and reputational damage. This column uses data on a popular blogger in Russia to show that blogs are critical of corruption in state-controlled companies can lead to decreased profit diversion and corruption by the targeted companies. Social media appears to play an important role in improving accountability, particularly when traditional media is censored or political competition is limited.

Igal Hendel, Saul Lach, Yossi Spiegel, 19 June 2015

It is well-documented that social media is an enabler of mass protests. Social media-led protests and how they interact with the economy are, however, less well-understood. This column focusses on boycotts of cottage cheese (a staple food) in Israel as a protest against increased prices and finds that firms seem to react to these threats and set prices not only on the basis of demand elasticities, as traditional analysis in industrial organisation assumes, but also on the basis of the business environment – something which is not easily captured by traditional analysis.