NY Fed, Report: What Has Driven the Labor Force Participation Gap since February 2020? 

“In this blog post we show that demographic trends, specifically population aging, exert a powerful influence on labor force participation. In other words, the participation gap largely disappears once we control for population aging, indicating that participation has recovered a great deal since the large shock induced by the pandemic. Other possible contributing factors, such as elevated retirement rates or disability, play only a minor role in explaining the participation gap. Population aging is likely to continue to exert strong downward pressure on participation going forward, as more of the baby boomer generation continue to enter retirement.”