"This paper investigates the causal impact of the media in financial markets by exploiting exogenous media blackouts resulting from national newspaper strikes in several countries. Trading volume falls by approximately 18% on strike days, while volatility is mostly unaffected. These findings indicate that the media influences investors’ trading behavior but not stock returns. They support theories in which information propagates gradually among investors thanks to the media but is incorporated immediately into stock prices as a result of arbitrageurs’ trades." (Quoted from paper)