re: #4 JordanRules
It shouldn’t come as a surprise that unions help workers across the board. A non-union shop, in theory, has to compete for labor with a union shop - if the union shop is offering higher wages and benefits, then the non-union shop has to offer better wages and benefits to get and keep workers.
As for the decline in union membership, that’s a whole other kettle of fish. Most people associate unions with manufacturing, and as our economy shifted away from manufacturing towards services over the last 30-40 years, unions lost ground because they weren’t necessarily in industries where workers were. Throw in the growing presences of automation replacing manufacturing jobs and the power of unions dropped even more.