Why not raise it to $25???

And They Want to Raise the Minimum Wage to $15.00

Economic Policy Journal

The number of teenagers in the workforce has collapsed over recent decades, increasing the minimum wage will only make things worse. The below chart shows the labor participation rate in the U.S. for those between the ages of 16 and 19.

Link:
http://www.economicpolicyjournal.com/2014/03/and-they-want-to-raise-minimum-wage-to.html