One way to possibly impose a maximum wage would be to make the maximum wage a corporation could pay someone (such as a CEO) tied to so many times the wage of the lowest paid employee/employee's of a company.
To have the best effect, such a law should be written so if a CEO wants to make an an executive salary, the lowest paid employees would have to be paid at least
a living wage.
Not only would this be a huge step toward solving the problems with keeping minimum wage in step with inflation and cost of living, but it would go a long ways towards alleviating poverty.