How responsible is the government for this wage gap, at least concerning America?
I mean, take away the amount of waste, corruption, and "lost" money that could have been put into how many cities and towns, to establish better schools, schools that were capable of offering the same level of education not void of resources. Imagine every inner city in America with the best public schools imaginable, 99% graduation rates compared to what reality is and has been. How much individual loss in terms of just human capital and opportunity has there been? It's hard to try and quantify that amount of loss.
Imagine local/city and states being able to bring in more companies, maybe, subsidize certain companies in less economically advantaged area's, where better employment and opportunity was afforded a citizenry that found upward mobility, instead of decay and loss of any advantages.
Think about the opportunity loss and cost of American industry that has left domestic manufacturing, that could have been saved by local/city and state governments, let alone federal dollars, that could have made for a much larger, and more productive and financially rewarded middle class.