When negotiating, what is an "impasse" and how should you deal with it?

An impasse is when you hit an issue that cannot be resolved. I you stay on an issue where an agreement in principal cannot be reached, the negotiation cannot move forward and will shortly end. It is best, therefore, to shelve the issue and move on to other issues that can be resolved. As each party gives and receives concessions on the other issues, positions often soften on the shelved issue and agreement can be reached near the end of the negotiation.