What do assoicates do if they do not make VP?

You can pretty much go and do anything you want in most other positions at the bank. If we're talking BB, it's usually easy to transfer to other positions (in other locations). People tend to look fondly on IBD types.

Because of the rigid and formal career progression in banking, it's tough to get in, but easy to move out.

I've never heard of an associate that didn't get promoted to VP (unless they were let go during downsizing). The only two promotions that are not "automatic" are analyst-->associate and Director-->MD.

I've seen a number of associates fail to make the promotion to VP. What generally happens is an associate that has been with a firm for ~3 years doesn't get promoted (promotions seem to come in waves). Then, after the next bonus cycle, the associate "decides to pursue other career paths." It's like a firing, but everyone gets to save face.

As for what they do, I've seen:

A) Go to work for the family business B) Pursue business development or M&A jobs at a corporation C) Stay unemployed and decompress D) Join prior clients in high level finance positions

Curiosity, how much does a third year associate make and how much does a 1st year VP make?

if you're at a BB and don't make VP then I'm sure it wouldn't be hard to move to a MM or Boutique and become VP... so long as your references etc. aren't like TERRIBLE.