"Engineers suck at negotiating, so don't negotiate, be fair." From http://blognewcomb.squarespace.com/essays/2010/10/14/cult-cr...
Many managers hire people as a sudden reactionary event ("we have an open rec, we've got to hire before the rec closes!"), leading to rushed hiring decisions, and then negotiation issues a year later where you ended up hiring someone (and they took the offer) out of immediacy / desperation, and the employee ends up leaving or accepts the lack of interest and doesn't work to his/her full potential.