What would happen if it really cost zero to hire a new employee? Or if hiring cost less than zero? Let's postulate an annual corporate tax deduction of $16015

What would happen if it really cost zero to hire a new employee? Or if hiring cost less than zero? Let's postulate an annual corporate tax deduction of $16015 for each employee working 30 or more hours per week. This would be compensated by increasing corporate tax rates until all changes are revenue-neutral. This probably means that every last person able to work could get a job warming chairs at $7.25/hr for 30 hr/wk. What unforeseen consequences could that have on the labor market?