Negotiation apparatus, negotiation method, and non-transitory computer-readable storage medium

A negotiation method performed by a computer, comprising:

• acquiring history information that indicates a proposal time of a current offer from an opponent and a utility of each offer from the opponent that has been received in a negotiation, a maximum length of time of a period of the negotiation being fixed in advance;
• generating a probability distribution of a number of future offers based on a length of time of a remaining period of the negotiation and the proposal time of the current offer;
• computing an expected utility of future offers based on the probability distribution of the number of future offers and the utilities indicated by the history information;
• and
• determining whether or not to accept the current offer based on the expected utility of future offers and the utility of the current offer.

A non-transitory computer-readable storage medium storing a program that causes a computer to execute:

• acquiring history information that indicates a proposal time of a current offer from an opponent and a utility of each offer from the opponent that has been received in a negotiation, a maximum length of time of a period of the negotiation being fixed in advance;
• generating a probability distribution of a number of future offers based on a length of time of a remaining period of the negotiation and the proposal time of the current offer;
• computing an expected utility of future offers based on the probability distribution of the number of future offers and the utilities indicated by the history information;
• and
• determining whether or not to accept the current offer based on the expected utility of future offers and the utility of the current offer.