Research by George Wu a professor of behavioral science at the University of Chicago Graduate School of Business, indicates even skilled negotiators may have underestimated the amount that it was possible to gain in a negotiation.

He states,

“When two people are negotiating over an issue such as price or salary, the amounts that each person is willing to give or take (i.e., their bottom lines) determine the range of possible settlements, commonly called the “bargaining zone” or “pie.” Put differently, the pie is the total value available for negotiators to split, and is defined by the size of the bargaining zone—the difference between the maximum amount that one person (e.g., a buyer) is willing to give and the minimum amount the other person is willing to take (e.g., a seller). There will only be an acceptable deal if one person is willing to pay as much as the other person needs. However, most savvy negotiators will not tell their counterpart how much they would really be willing to pay or accept. While each person might have ways of developing informed guesses about the other’s situation, perfectly accurate guesses are hard to come by, and mistakes are inevitable.”

Be sure you get your fair share.