The traditional, adversarial approach to negotiating, taught in books, seminars, and business courses all over the world, is a reductive approach: each side seeks to gain as much as possible by minimizing the value obtained by the other. If both parties are "tough negotiators," they'll succeed at the second objective and fail at the first. The result: minimum value for both sides. The age-old rules are known; keep your "opponent" guessing; don't give away too much information about yourself or your needs; negotiate from a position of strength and force your "adversary" to negotiate from...