Background Noise? TV Advertising Affects Real-Time Investor Behavior
利用分钟级电视广告数据，研究发现广告播出后15分钟内，投资者对广告公司的在线信息搜索量增加3%至8%，交易量随之上升，且主要由散户驱动。
Using minute-by-minute TV advertising data covering some 300 firms, 327,000 ads, and $20 billion in ad spending, we study the real-time effects of TV advertising on investors’ searches for online financial information and subsequent trading activity. Our identification strategy exploits the fact that viewers in different U.S. time zones are exposed to the same programming and national advertising at different times, allowing us to control for contemporaneous confounding events. We find that an average TV ad leads to a 3% increase in EDGAR (Electronic Data Gathering, Analysis, and Retrieval) system queries and an 8% increase in Google searches for financial information within 15 minutes of the airing of that ad. These searches translate into larger trading volume on the advertiser’s stock, driven primarily by retail investors. The findings on retail investor ad-induced trading are corroborated with hourly data from Robinhood, a popular retail trading platform. We also show that ads induce searches and trading of companies other than the advertiser, including of close rivals. Altogether, our findings suggest that advertising originally intended for consumers has a nonnegligible effect on financial markets. This paper was accepted by Karl Diether, finance.