... Yeah, i believe it. McDonalds did their own internal study in 2012 to see what raising the wages of everyone enequivalent of paying their lowest paid 12.50 an hour (so, not just raising the minimum, everyone would have gotten the same ~6.00$ raise) would cost the company. The answer? About a 4% drop in PROFIT - not gross receipts, just Profit. Or, they could pass every single penny on to the consumer and it would have cost about... 4 cents per MEAL.
People have a VAST misconception of what part labor costs play in a lot of businesses, PARTICULARLY big mega-corporations.
It would be a little worse for 'mom and pop' places, but even they can make a decent profit. Here in MI there is a small (but growing) chain called Moo Cluck Moo - burgers and chicken, fast food joint. Owner pays ALL employees 15$ an hour or more, AND all the food is farm-to-table - locally sourced, including the soda.
A meal there costs maybe 1.50$ more than McDonalds (Burger, Fries & Drink is about 8.50$) - but id pay that just for the increase in quality - the food is amazing compared to any chain fast food joint and better than a lot of sit-down places - and in addition, the staff is always super pleasant and helpful and the restraunt is always spotless... And yet, the owner still makes enough to drive a jaguar, own a nice house, and expand the business (and is opening a similar chain of artisan pizza fast-food places).