The functions of a union in a "free market" economy is a difficult thing to rationalize. In such an economy there is suppose to be many producers serving many consumers with the result that the consumer gets the best products at the lowest prices possible. If a producer does not compete he fails.
The theory is on solid footing in a free market; however, it breaks down if the market instead is controlled by an oligopoly or monopoly. In this instance, the producer no longer cares as much about the wants and needs of the consumer. He will produce the cheapest product possible and charge the highest price because the consumer has no choice.
In the perfect world, labor will deliver their product, their labor, to the producer under the guidance of a free market system. The problem is we do not have a free market when it comes to labor. Usually one union represents labor at one company and often within one industry. Therefore, labor has the opportunity to "extort" wages and benefits that are potentially much higher than a free market would allow. In a global economy this results in goods coming from a foreign country to be cheaper than what is produced within the United States.
No one has come up with a solution to this problem, including myself. Perhaps we need to treat labor in the same manner as utilities. We have accepted the fact that our electricity providers in this country need to be of such a size that it does not permit more than one company to be able to provide electricity to large regions of the country. Further, the cost to be a provider of electricity is so costly that it limits who can enter the business. As a result, we have deemed them to be a utility and must be regulated so their influence and power is not abused.
Is this what we must do with labor?