The investigators used Facebook ads to show a 20 second video clip recorded by Massachusetts General Hospital, Harvard and Lynn Community health center doctors (6 people in all) to approximately 20,000,000 Facebook users. The ads will be shown before the Thanksgiving and Christmas holiday and will focus on staying safe - limiting travel and mask-wearing. The investigators will randomize exposure to the ad campaign at the ZIP code or county level to ask:
Do the videos change mobility and Thanksgiving and Christmas holiday travel? Do they reduce the spread of COVID-19?
Are there spillover impacts from the video messages? For example, if individuals decide to stay home, then do the geographical regions that tend to be visited by people from treated areas experience any effects, either through information spillovers or through a reduction in travel?
