基于CARA效用函数的报童决策偏差形成机理

Formation mechanism of newsvendor decision bias based on CARA utility function

经典报童模型假设决策者为风险中性,但决策者的实际订购行为受风险偏好的影响,导致实际订购行为与报童模型最优解之间存在偏差.为此,基于常绝对风险厌恶(CARA)效用函数构建库存决策模型,从风险偏好的角度解释报童决策偏差的形成机制.行为实验结果表明:随着产品的相对成本增加,决策者的订购行为将出现风险逆转;在高(低)利润产品中,决策者分别表现出风险规避(风险追逐)的订购行为,且订购行为受风险规避的影响更为显著.报童决策偏差现象揭示,库存管理实践中考虑决策者的风险偏好,有利于缩小理论模型与管理实践之间的差距,提高库存管理效率.

The classical newsvendor model assumes that the decision maker is risk-neutral. Since the decision maker’s actual order behavior is affected by risk preference, there is one deviation between the actual order quantity and the expected profit-maximizing order quantity. Based on the constant absolute risk aversion（CARA） utility function, the formation mechanism of newsvendor decision bias is explained from the perspective of risk preference. The results of behavioral experiments show that the decision maker’s risk preference will reverse with the relative cost increase. The decision maker exhibits the risk aversion（love） order behavior under the high（low）-profit market. Furthermore, risk aversion has more significant effect on the decision maker’s order behavior. The newsvendor decision bias reveals that in the actual inventory management, considering the decision maker’s individual risk preference is beneficial to diminish the deviation between the theory model and the practical situation, so as to improve the inventory management efficiency.