[mnm1]

If the salary is already negotiated, it'd be extremely demoralizing for the company to force the employee to take less. A company that's willing to pay less because one lives somewhere else after one has proven oneself is a company that has the least engaged, most demoralized employees possible. The productivity lost is undoubtedly many times higher than what was saved in COL adjustments. It's amazing how brain dead most companies are, so focused on intermediate goals to the major detriment of the entire company's progress. This is one prime example. Another is not giving yearly raises, at least to adjust for inflation. Or lowering benefits. If the benefits are still good, people will stick around and put in the minimum.