The formula to calculate the Wage Decrease Percentage is:
\[ \text{Decrease} = \left(\frac{\text{Original Wage} - \text{New Wage}}{\text{Original Wage}}\right) \times 100 \]
Where:
Let's say the original wage is $20 per hour and the new wage is $15 per hour. Using the formula:
\[ \text{Decrease} = \left(\frac{20 - 15}{20}\right) \times 100 = 25\% \]
So, the wage decrease percentage is 25%.