I explained why raising the mnimum would not affect unemployment in my previous post and don't want to do it again here.
I don't know where you see anything that i wrote that talked about doubling expenses or anything like that. As far as it goes, small businesses don't compete with Walmart. If Walmart wants to they flatten them, they are done. Walmart does it with imported crap. I don't know why people shop there. As far a McD's or burger joints, I don't eat that stuff any more so I'm not up to date on their costs or cost structures. I managed a burger joint when I was a kid. Labor costs ran roughly 20% of gross expenses*. Wages at or slightly more than the current minimum didn't affect it much -- sales and management practices had a much larger effect. I don't know what current margins are but doubt they are higher than what I saw.
The thing is, the minimum wage is not a livable wage. I'd like to see a more serious effort to enable people to move into better paying jobs where there is already serious shortages. And you know what? I bet you'd make a great employee in one of the areas where there is a shortage of workers, like electrician. But you need training, which circles back to how I'd like to see more effort made in this area.
A belly ache of mine is how big business is always crying about how trained labor is not available, yet they lay people off at the drop of a hat. Why would a kid take years of training just so they can get batted about by poorly managed companies? If they want people to want their jobs, companies might try to make the jobs attractive.
Anyway, I don't think your gripe was about my look at the economics of the minimum wage, it has more to do with everything else going on. It sounds to me like you are dissatisfied with where you are at and that is as good a starting point as any for figuring it all out. Good luck.to you.
*edit: it was actually 20% of revenue.