The ‘covid & not LC’ category is notably more productive than the ‘no covid’ category in both combinings, which seems interesting.
My guess is that it’s probably the combining methods, given the different results by modality. But if I had to come up with an explanation for the trend: some people tried hard to avoid COVID, which involved making their lives worse, and some people didn’t. If you didn’t try hard to avoid COVID, you then contracted short COVID, and got a productivity boost against the no-COVIDs by living your life normally, but no serious productivity loss from COVID.
My guess is that it’s probably the combining methods, given the different results by modality. But if I had to come up with an explanation for the trend: some people tried hard to avoid COVID, which involved making their lives worse, and some people didn’t. If you didn’t try hard to avoid COVID, you then contracted short COVID, and got a productivity boost against the no-COVIDs by living your life normally, but no serious productivity loss from COVID.