In negotiation, the Zone of Possible Agreement (ZOPA) refers to the range where two or more parties can find common ground and reach an agreement. For instance, Chris wants to sell a used car for between 2500, while Sally, the buyer, has a maximum budget of 2000 and $2200 in this case, and the final selling price depends on how effectively the two parties negotiate at the table. We say the ZOPA is negative when the two partiesโ€™ ranges do not overlap, and there will not be an agreement that can be reached in this situation.

An informed and accurate ZOPA estimate is a critical step in negotiation preparation. Understanding the other partiesโ€™ range will help you anchor the negotiation starting point and claim the lionโ€™s share.

As with every other negotiation preparation consideration, a perfect estimate of ZOPA is often impossible. However, you can create, extend, shrink, or shift a ZOPA by asking the right questions during the negotiation to gather more information and eliminate assumptions. Thus, you could enter a negotiation with an estimated negative ZOPA and still reach a satisfying agreement.