Question

If the government imposes a payroll tax on a monopsonist, do the wages go down along with the employment?

Answer 1

Your request is not too clear.

Here's a definition of the word "monopsonist" = monopsony
the market condition that exists when only one buyer will purchase the products of a number of sellers. — monopsonist, n. — monopsonistic, adj.

In any employment, if you must pay a payroll tax, your take-home pay is lessened by that much.

Sra