It looks like this is the equivalent of a preprint. So, while an interesting finding, a general reminder to take it with a grain of salt and recognize that there might be issues in the statistics (maybe confounding variables that weren't controlled for) that would lead to revised results if fixed, and we've also seen peer reviewed publications like the Lancet paper that were also hit with data integrity issues. It's a good data point to keep in mind, and you should probably be wearing a mask, but we'll need a meta-analysis of a lot of these studies over the next year or so to know to any level of certainty how much they actually helped. That's not useful for our behavior right now of course, but in terms of drawing conclusions, always keep in mind that initial analyses lime this are just that, initial. From the paper:
"IZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper
should account for its provisional character. A revised version may be available directly from the author."
"IZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author."