Is there an economic reason why employees don't share salary information with each other? In Western society, one's salary is often a taboo topic and people tend to not tell other people what they earn. 

In China by contrast, I have been told that asking one's salary is fairly normal social discourse. 

It seems that employees being aware of each other's salaries would be an advantage, as they have more information about what the organization is willing and able to pay. 

Is there an economic reason why people don't reveal their salaries, or is this entirely a cultural taboo?
dwjohnston,

To answer your question briefly: no, because it is rather a social or psychological matter than it is an economic matter.

There is already asked a good question about this subject in The Workplace community: https://workplace.stackexchange.com/questions/15397/why-is-discussing-pay-such-a-taboo-how-can-i-get-people-to-talk-about-concrete/15431#15431

Feel free to read the (also good) answers. The answer section also contains some handy tips and tricks that you and your co-workers could try.

I hope this will be useful for you.