Whatever your stereotypes about wealthy private schools, it doesn’t apply to their faculties. Private school teachers make way less money.

The gap is larger for some groups (like elementary teachers), and smaller for others (like teachers with Doctor’s). But at all levels of experience and education, the chasm persists.

Public v. Private - teacher salaries, selected groups

Explaining this gap isn’t so easy. The following causes all seem to play a role:

  • Different teacher characteristics. Private school teachers are more likely to be rookies, and to lack a teaching credential or even a Bachelor’s.
  • Public-school teachers have unions advocating and negotiating on their behalf; private-school teachers don’t.
  • Conditions are better at private schools, so teachers may take a pay cut to work there.
  • Private schools have far fewer jobs to fill (less than 500,000, versus roughly 3.5 million public jobs), and more applicants meeting the qualifications (since they’re not limited by law to licensed teachers). This changes the labor market dynamics.

Source: National Center of Education Statistics

Disclaimers: Writing for The Atlantic, I attributed the gap in large part to conditions. I haven’t come across good data that would let us tease apart these causes, though.