[sce]

If the employer responds by increasing the prices of the goods/services they sell, then yes. However, in the market the consumers have a choice, so they can choose to not buy something, or buy somewhere else, and the market thus regulates itself. Don't want to pay taxes? Not much choice there. So I think having the market regulate itself is better than enforcing the cost of labor through taxes. (Who knows, maybe the employers would be forced to cut their margins even.)