It’s not just that top people are receiving multiple job offers … although we are seeing plenty of that. It’s not just an increasing self confidence level that makes candidates more willing to ask for what they want … although we are seeing plenty of that also.
No, the really interesting development is how well-informed candidates are. They really know, within a few thousand dollars, exactly what they are worth. That’s a long term shift that employers ignore at their peril. You simply must assume that both parties to the job offer have very similar information now–they know what you know.
As an employer, you simply cannot low-ball an offer by a few thousand and hope the candidate will fold–when you do that now, you only snatch defeat from the jaws of victory and end up with nothing.