Unions are there to protect the rights of the workers, which believe it or not, are often disregarded when the workers don't know what they're entitled to and the kind of treatment they don't have to subject themselves to. Such as discrimination, disparagement of treatment, forced demands, etc.
For example, when I was 18 I was naive about a few things until my father explained them to me. For one, you can't work off the clock, and if you're forced to, you have to notify wage-an-hour and it becomes a mess after that (one thing with which I was asked and manipulated in to doing many times, because I was 18 and was scared to death I'd get fired if I didn't wait on my boss hand and foot). In my job at the time, they didn't have unions, so it was up to the workers to know their rights, and defend them when their bosses got out of hand with their demands. I've gone 12 hr shifts before without any 15 min breaks, or a 30 min lunch break. I was hurt on the job, and given a hassle when I called out the next 2 days because I couldn't come to work. I was asked to work off the clock so my hours wouldn't spill in to overtime which would rain on my bosses parade from the corporate bosses. And I was forced to take shoots (I was a studio photographer) with abusive customers (one time a woman grabbed me and shook me), and animals I was not comfortable with or was allergic to. It didn't dawn on me until I had a talk with my dad 6 months later that I had the option to say no to all of these things, but I didn't know this because we didn't have a union and I was too young to know that jobs came with workers rights.
Another thing I can say for Unions, is if it weren't for them, my father would have been treated like dirt, and probably let go ages ago because he has seniority and they don't want to pay him the money he's spent 20 yrs earning and deserves.
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Ok. Think of is this way. The whole purpose of a union is for the workers to negotiate with their employers, right? Well, unions can get out of hand. Workers start asking for wages that are basically, not within reason. They threaten to go on strike, so the employer is basically forced to appease said workers and give them a high salary. However, if you have laws preventing this kind of behavior, then it won't get out of hand, and the employers do not have to pay out higher wages, which stimulates the business, and ultimately the economy.
The entire purpose of a union isn't just to negotiate demands from the employee's with the employers. It's also to protect the rights of the worker so employers don't overstep boundaries, or force demands on the workers. It essentially, gives the workers a voice that employers/businesses will listen to. The worker themselves are often disregarded in their demands because it's just 1 person or multiple people in separate accounts. But when you come together, to form a union, your demands can be heard better.
(Source:
http://unionsact.org.au/index.php?option=com_content&task=view&id=4&Itemid=8)
Explains what a unions purpose is, and what a union in the workplace itself is.
This is a link explaining Australia's labor union, but it's the same essential idea for the guidelines and explanation of what unions are about.
The sections to focus on are the ones that correlate to this statement.
