actually doesn't exist in any concrete way except in some niche industries.
Example.
American Airlines just pony'd up huge raises for their unionized staff. Raises that would not have been possible in a non-union shop.
American is still making massive profits.
http://www.usatoday.com/story/money/2016/08/05/american-airlines-twu-iam-association-pay-increases-us-airways/88293206/