A minimum wage is a very important boost for productivity, as several management studies say. People could also use the additional revenue for themselves, for example, to improve their health. All of these factors have a positive effect on economic growth by improving social capital.
Employers are forced to demand higher productivity as a consequence of being forced to pay more for each employee. Skilled and experienced employees are made all the more valuable, but at the expense of others who don't have those advantages.
Higher skilled workers will have a natural resentment towards lower skilled because they might fall into the same wage levels. This resentment will kill productivity as the higher skilled workers will be demotivated to produce more.