If I hadn't deleted my Twitter account, I'd give Zaius 140 characters of what-for. Instead, I'll point you to this tweet of his:

RT @HeartlandInst: Northwestern U. study: raising the min wage doesn't help low income workers. Who wld have thought? http://bit.ly/c6KfZH

Who indeed? But somebody might as well point out that it's not a study -- but a theoretical model. That model might well be correct. But if you read all the way to the last couple of paragraphs of the link...

So far, the model remains a theoretical pursuit. “It screams for empirical testing,” Swinkels says. “We hope that it will excite empirical activity by people better qualified at that than ourselves.”

Well, uh, I'm going to go ahead and wait for some of that empirical testing before I draw much in the way of conclusions. Besides, it's worth noting that the model doesn't really account for the "minimum wage" writ large -- it instead looks at those jobs where employees receive some combination of minimum wage and "incentive pay" -- tips and commissions. There are lots of minimum wage jobs that don't fit those conditions. So even if the model proves correct, its application is limited.