I agree with HQ but for slightly different reasons. Raising the minimum wage won't change income disparity as long as Quirk's books wants to make X* his employee's minimum wage. As one goes up so will the other.
If a certain group of people want all the marbles then the number of possible marble games drops to *ahem* 1%.
A guy who makes 365 times what his 50k/yr employee makes doesn't buy 365 times more groceries, cars, beds, shoes, and so forth. He stockpiles money and doesn't stimulate the economy.
If he could be contented with making 20 times his 50k/yr employee then he could hire 340 more employees or double the pay of 680 his 25k/yr employees and they for certain would spend the shit out of that money and that would help the economy.
Ultimately you can't legislate for morality or against greed, if you could no one would try to find loopholes.