> If you've a gram of experience you should realise it's generally in your own best interests not to tell your colleagues what you're on.
Don't patronize me. I'll decide what is in my best interests thanks.
> I don't see where the exploitation comes from.
exploit - 2nd definition from google:
> make use of (a situation) in a way considered unfair or underhand.
The company is taking advantage of the fact they are the only party that has access to the information on what everyone is paid in order to benefit by paying some people less than others.
The company has a maximum that they will pay but is not telling the workers what that is, and even going so far as to make rules to prevent the workers discussing amongst themselves.
You are arguing that these circumstances are somehow a free market while simultaneously accepting that one party is artificially and unfairly impeding the free flow of information.
A free market requires informed consumers and the company is well aware of that.
The workers should be able to decide for themselves if they agree that "preventing jealousy" is a strong enough argument to justify manipulating the market. If they think it is, then fine, they are free to decide to keep their pay private.
As a party that stands to benefit, it is not up to the company to mandate what is in the best interest of the workers. That is the definition of a conflict of interest.
In my opinion, any rule that attempts to stifle communication between workers is overstepping a company's authority.