A Harvard Business School Working Paper by Joshua Coval. An excerpt:
Which schools chose to favor teacher interests over those of their students? The answer turns out to be quite simple: it was those schools that had demonstrated a willingness to do so in the past. Schools that chose virtual instruction during the 2020-2021 school year were schools that, prior to the pandemic, had a history of favoring teachers over students. During the 2018-2019 year, students at schools that would later opt for online instruction had school days that were 18 minutes (4 percent) shorter. Their teachers spent 30 fewer minutes at school each day and 1.5 fewer non-teaching days at school each year.