(A recent study by the Department of Sociology at Princeton)...
...paid for by the taxpayers.
Not necessarily: there aren’t that many government grants for sociology, and Princeton’s endowment is so large they can pay $23K stipends to graduate students for five years in exchange for three semesters of teaching and offer them subsidized housing and health insurance throughout. There’s a good chance this was simply the research done for a Princeton Ph.D. dissertation in sociology and cost the tax-payers not a dime.