I don't have the last 10 year data, but from ~2000-2014 the pupil-teacher ratio was flat and at all time recorded lows. This works against the thesis there is a shortage relative to post WW-II history.
It appears whatever teachers is paid, the feeling they get from helping kids vs building cogs for evilCo must be enough additional incentive to keep us near record low pupil-teacher ratio.
https://nces.ed.gov/programs/digest/d16/tables/dt16_208.20.a...