A utility concession curve data fitting model for quantitative analysis of negotiation styles

• A reciprocal function is proposed for defining the utility concession curve.
• An optimization model is proposed to fit the concession curve to a set of offers.
• Quantitative analysis of curves is now possible using the utility curve center (w).
• Experiment data has 3 cluster; slightly collaborative, neutral, quite competitive.
• Competitiveness of the counterpart increases the negotiator’s competitiveness.

A reciprocal function is proposed for defining the utility concession curve of a negotiation participant. The curve has only one free parameter and can fit the complete range of negotiation styles from extremely competitive to extremely collaborative. Various equations are derived, including the definition of a utility concession curve center which permits intuitive quantifying of a utility concession curve. Subsequently, an optimization model is proposed to fit the curve to a set of offers. Using the proposed model, a set of negotiations is mined for utility concession curves which are then used for clustering and hypothesis testing. Three negotiations styles seem to emerge from the data; slightly collaborative, neutral and quite competitive. It is also shown quantitatively that the level of competitiveness of the counterpart is negatively correlated with the agreement rate, and this is validated against the experimental treatment. Additionally, by the use of an experimental treatment, it is shown that the level of competitiveness of the counterpart has a positive causal impact on the negotiator’s style, causing him to become more competitive or collaborative. The data fitting model can also be used for incrementally fitting the curve in real-time during a negotiation to provide an estimate of the negotiation style which may help in the negotiation process.