(1) There is no rational basis on which to raise compensation according to productivity, unless the employee herself is the reason for the increase in productivity. The hours-per-ton of coal mined today is multiples of what it was 30 years ago, but the actual miners' jobs are quite a bit easier and safer. The difference is improvements in mining equipment, in which the miners themselves played no part. Why should the miners be paid more?
(2) The very existence of a statutory minimum wage is economically stupid and counterproductive, as any honest economist will admit (even Paul Krugman, in his textbooks). Compensation should be set according to supply & demand, just like the price of just about everything else.
(3) The Minimum Wage law is unconstitutional. The ninth amendment alludes to many other rights that are not enumerated in the Bill of Rights, but are to remain in existence nonetheless. One of those rights (coming down to us from English Common Law) is the Right of Contract. The right of contract is basically the right of any person to contract for anything they desire with another willing person, as long as it is not illegal (prostitution, sales of stolen goods, etc.). Minimum Wage laws prohibit willing employers from contracting with willing employees for any wage that falls below the statotory minimum wage. That is, if I want to pay a high school kid $5/per hour to do odd jobs around my fruit market after school and on weekends, and he wants to do it for $5, WE ARE PROHIBITED BY LAW FROM ENTERING INTO THIS CONTRACT (oral or written). Thus, the MW law is unconstitutional.
(4) If it is SO ******* important to raise the MW, why didn't the democrats even attempt to raise it when they had control of the White House and both houses of Congress in 2008-2010? They managed to stuff ObamaCare down our throats.
(5) The one question the Libs refuse to consider seriously is "Where does the money come from?" What they actually believe but cannot say out loud is that The Rich Business Owners will be forced to pay it out of their "obscene profits." But clearly, the money will either be taken out of the pockets of customers (YOU), or will be made up by other means. See (6) below.
(6) Any time the State mandates that the price of something be greater than its economic value, three things happen: (a) the consumers of that commodity use less of it, (b) the consumers will seek alternatives, and (c) a "black market" comes into existence to satisfy the need. Let's say the government mandates that the price of a bag of potato chips be $10. (a) Consumers will purchase fewer bags of potato chips, (b) they will seek alternative salty snacks, and (c) "underground" producers will start making and selling potato chips out of the trunks of their cars. For $8 a bag.
In the case of a MW mandating wages beyond the ecomonic value of the services provided by bottom level workers, (a) takes the form of reduced hours and employees, (b) is automation and outsourcing, and (c) is hiring of "undocumented workers," and paying people "under the table." Again, its economic law, not subject to the whims of Congress or the President.