Raising the minimum wage at all for any reason is a terrible idea.
If you were to raise it up to 15 dollars an hour, what you would really
be doing is lessening the value of the dollar as a whole. What you
would end up with is creating a system where $15 now has the
purchasing power that $7.25 had before the raise.
The money would not retain its value, because the value of money is
not really based off of gold or an arbitrary number, it is based off
of the time, resources, and effort people spend to earn it.
Time is quite literally = money.
I will use gold as an example though. Gold is expensive because it is
rare. Rareness means that it takes a significant investment of time
and resources to mine it, you can't just find it laying around on
every street corner. If you were able to create gold and give a huge
lump of it to every single person in the country, gold would be worth
much less because it would no longer be rare.
Increasing the amount of paper money in the general population would have the
same effect. Money has value because not everyone has a lot of it, and
it costs time and resources to earn, but it has no more value than
what people ascribe to it. if $15 required the same amount of time and
resources that $7.25 did before, than $15 would become the new $7.25.
If you raised the minimum wage, in the short term the people who live
on those wages might have an easier living for a few months, but
eventually the system would balance out, and they would be asking for
$20 an hour for living because they can't survive on $15.
Also, by giving everyone more money, you actually hurt more people.
When the min wage goes up to 15 an hour, the guy who currently makes
16 an hour is not likely going to get a raise to compensate right off
the bat. Prices everywhere will go up because it costs more to hire
and train people, and Mr. $16 an hour will find he has a much higher
cost of living than he did before. People in his income bracket and
the middle class will suddenly find themselves worse off than before,
at least until the system evens out and $15 has the purchasing power
that $7.25 did before, and the guy who made $16 is now making $27, but
living the same as he did before the switch because now he is paying
$2.50 for a taco that used to cost $1.
In other words, raising the minimum wage is purely cosmetic. It hurts
as many as it helps in the short term, and does NOTHING in the long
term.