Unions have helped create positive working conditions in this country that would have been unimaginable 100 years ago. One needs look no further than the history of the development of the Fair Labor Standards Act for proof. Every major advance in working conditions in America has come about through unions advocating working conditions that were humane and just. These pioneers fought for a better life for all working people. Because they saw themselves as representatives of an otherwise unrepresented class, their personal advocacy was transformed into social advocacy.
It is not from the benevolence of the butcher, the brewer, or the baker, that we expect our dinner, but from their regard to their own interest. Adam Smith.
A friend of mine shared an idea with me about how unions, when working correctly, provide layers of advocacy. The fullness of this concept is developing for me, but its general implications appear to be applicable to any institution with collective bargaining groups as constituent parts of it.
If a teachers union in a primary or secondary school makes specific demands for better working conditions: higher salaries, smaller class sizes, better pensions, etc. it simultaneously advocates for better teachers. A fundamental principle of free market economics is that when better conditions of work are present, more and better people will be attracted to the work.