Answer:
Frictional unemployment cannot by itself explain the fact that the late 2010s saw more job openings than unemployed workers.
Instead, frictional unemployment points to the fact that some people are unemployed because they are just entering the labor market for the first time after a long period of absence.
Step-by-step explanation:
As a part of natural unemployment, frictional unemployment arises when workers search for new jobs or transition from one job to another. During economic recession, there is no increase in frictional unemployment. Typical examples of frictional unemployment are caused by graduating students who join the labor force and are unemployed until they find work and parents who rejoin the workforce after taking sometime to stay at home and raise their children.