The researchers wrote: “At the start of the pandemic in February 2020, there were 13.6 million non-US citizen (immigrant) workers. By April 2020, that number had fallen to 12.2 million: Roughly 1.4 million fewer immigrant workers were in the labor force.

After the pandemic, however, the economic recovery was unprecedently sharp, with the unemployment rate returning to pre-pandemic levels by July 2022.2 Additionally, the vacancy-to-unemployment ratio, a measure of labor market tightness, was unusually high, peaking at 2.63 in April 2022.”

PFR:  the count of foreign born has fluctuated much since the late 2010s and this is one example, so it needs to be taken with a grain of salt. That said, the workforce in early 2020 was about 165 million. The research essentially shows that a reduction by 1.4 million in the workforce was not enough to have any material impact on scarcity of workers except where the share of workers who are non-citizen immigrants is high – which is in the food services industry.

Very roughly 30% of cooks in the U.S. are foreign born and 25% of all other food services workers are foreign born.  This is a highly mobile, high turn over workforce, willing to switch jobs for better conditions, probably much faster than in other lines of work which employ a lot of foreign born workers such as farming and IT. 18% of all workers are foreign born (including naturalized and non-naturalized).