Dear Matt: I was offered a new job that I accepted. When I told my boss I was leaving I was presented with a counteroffer to stay. This is making the decision to leave hard. What is the best way to handle this situation?

Matt says: It's almost never a good idea to accept a counteroffer, says Kathy Northamer, district president of Robert Half Technology (rht.com) and The Creative Group (thecreativegroup.com). Counteroffers may appear flattering and ego-boosting on the surface, but the drawbacks are significant.

"By accepting a job with another company, you're breaking the trust you shared with your current manager and colleagues," said Northamer. "Your manager may feel you are disloyal, while the rapport you've built with your peers could suffer. Your manager will most likely question your commitment to your job, which could make you more vulnerable to future layoffs."

Most of the time a counteroffer is a short-term fix that allows the employer to minimize disruptions and lost productivity. Northamer recommends this: Let your manager know that you appreciate the offer, but you've decided to join the other company. Here's why:

Money isn't everything. Remind yourself why you considered a move in the first place. Were overworked or under-challenged? Higher compensation won't erase those problems.

You've tipped your hand. Your employer now knows that you have an eye on the door and may view you as a temporary part of the team -- one who may even be moved to the front of the line for any future staffing cuts.

Secrets get out. Chances are your coworkers will find out that you not only tried to leave but also were rewarded handsomely for not doing so. They're bound to resent you.

Name decay. The damage to your reputation won't be limited to your boss and coworkers; the other firm may take an even darker view. At best, they'll feel relieved to have narrowly avoided hiring someone whose word can't be trusted. At worst, they'll assume that you were only using them to negotiate a raise. Either way, you've created a network of people who associate your name with broken promises and wasted time.

The boomerang effect. Counteroffers often end up magnifying the shortcomings of your current job. Even a boost in pay won't be much solace if you've damaged your relationship with your boss and stunted your career prospects inside the firm and out. "Before long, you may find yourself once again seeking a new employer," said Northamer, "only with more urgency and fewer options."