重設員工選擇權之執行價的議題過去已導致相當多的爭議。由於Kahneman和Tversky(1979)提出展望理論來主張人們一般會呈現展望理論的效用型態，我們的研究將員工之風險偏好與展望理論相結合。本篇研究目的為嘗試新的見解來說明重新定價之合理性。我們的模型提出新的重設執行價策略為股價漲時重新定價。以展望理論為基礎，從事前觀點下檢視員工在面對獲利或損失的狀態下，此模型顯示重設員工選擇權執行價具有必要性。從此本文顯露出股價漲時重新定價的重要性。關於重新定價，我們發現最佳激勵契約的決定性因子為員工之風險偏好強度。除此之外，在我們重新定價最佳化的過程中，員工與股東(主理人)之間利益存在衝突。如果具有強而有力的工會可以調解員工與股東之間的利益衝突，此時確保所有參與者彼此的利益較佳。因此，工會的角色對於重新定價應具有價值。

The issue of repricing has provoked many controversies. Since Kahneman and Tversky(1979)proposed prospect theory to claim that people commonly exhibit prospect theory type utility function, our study incorporates executive's risk preference with prospect theory. The intention of this study is to try to provede a novel insight into explaining rationality of repricing. Our model provides a novel resetting policy called up repricing. Based on prospect theory, this model shows that resetting is necessary for executives not only in the domain of gains but in the domain of losses from an ex-ant point. Thus this study teveals the importance of up repricing. In respect of repricing, We find that executive's intensity of risk preference is a decisive factor in optimal incentive contract. In addition, there is a conflict of interest between employees and stockholder(principal) in our optimal repricing process. If strong worker union con conciliate the conflict of interest between employees and stockholder, it will ensure that all participants are better off. Therefore, the role of worker union should be valuable to repricing.