What happens to the quantity demand of labor when governments establish a minimum wage?

What happens in this case is the labor market loses jobs. In the job market there is a chain of supply and demand just like there is in the product market. So what happens is the quantity of labor demanded goes down, and the quantity of labor supplied goes up. There becomes a surplus of workers who didn't get jobs and those are unemployed.

Fiscal policy because it refers to the use of government spending and tax policies to influence macroeconomic conditions, including aggregate demand, employment, inflation, and economic growth.