I think this paper's methods are suspect. They are 'measuring' politic spend/targeting in 2016 by assuming that price increase for a specific targeting segment

I think this paper's methods are suspect. They are 'measuring' politic spend/targeting in 2016 by assuming that price increase for a specific targeting segment = more targeted political spend to that measured audience. But political spending is a tiny % of FB spending. I strongly doubt this method gives any actual insight, first into what/who these campaigns spent/targeted in 16, and second on the persuasion effect of that spend. Also how would you control to only FB ad exposure effect using the survey data mentioned in the paper... I actually buy FB ads for political candidates as a big part of my business. We've done some 'lift/persuasion' type experiments where we do 1:1 targeting with a control group and do an IVR to measure changes pre and post exposure. This feels like the best way to do this experiment - but that would require academics to work with actual spenders (or to spend themselves). I actually really wanted to use FB's new attribution reporting with voting results this year but our accounts weren't given access until like a couple days before election and it wont let me look back in 'time' (e.g. we uploaded 'votes' as a purchase with the voted date timestamp, but FB will only show attribution window from date we setup the reporting tool, which is after the votes...).