This may be true for some bosses, but it's not a good general rule. You often don't hear about it, getting an outside offer and a raise happens all the time, and within a month it's pretty much forgotten.
If you present it by saying "I really love it here and want to stay, but the compensation being offered here is really good," then your boss should be fine. If your boss can't handle a business negotiation, then you should be looking to get out anyway.
Bottom line: it's a market, and you have to negotiate. Once the papers are signed, things usually go back to normal.
you know what else should be stressed? collective bargaining..it helps sometimes when your fellow coworkers band together to get a raise or to make the work environment better.
Has there ever been a controlled study about whether collective bargaining leads to higher wages in the long run? (Excluding effects like lobbying for restrictions on entering the market.)
From what I know, I can't rule out that collective bargaining for higher wage is like advancing the tide with a bucket.
in my experience they abhor what you get when you start handing money and power to the collective, and stop paying attention to what it's doing to you.
If you present it by saying "I really love it here and want to stay, but the compensation being offered here is really good," then your boss should be fine. If your boss can't handle a business negotiation, then you should be looking to get out anyway.
Bottom line: it's a market, and you have to negotiate. Once the papers are signed, things usually go back to normal.