期权工具存在下的最优混合采购策略研究

摘要

A manufacturer’s optimal procurement strategy combining option contracts, long-term contracts, and spot pur-chases is studied when raw material prices and demand are uncertain. And a purchasing model is built for a risk-averse manufacturer based on expected utility theory. The manufacturer’s optimal purchasing strategy is obtained if the utility function is quadratic. The results show that the relationship between optimal purchasing quantities and the degree of risk aversion depends on the magnitude of the expected price, the long-term contract price and the option price. The long-term contract quantity increases and the option contract quantity decreases, as the drift rate of price increases. However, the long-term contract quantity decreases and the option contract quantity increases, as the price volatility or the long-term contract price increases. And the expected utility of the manufacturer can be improved after adopting a combined strategy.%原材料价格与需求不确定下，研究制造商混合期权合约、长期合约、现货采购的最优采购策略。利用期望效用模型建立了一个风险规避制造商的决策模型，并得到效用函数为二次效用函数下制造商的最优采购策略。研究结果表明，制造商最优采购量与风险规避度的关系取决于原材料期望价格与长期合约价格以及期权价格间的相对大小关系；当价格漂移率增加时，长期合约预定数量增加，期权购买量减小；当价格波动率或长期合约价格增加时，长期合约预定数量减少，期权购买量增加；采用混合采购策略可提高制造商的期望效用水平。