注定的失败:沉没成本与南宋对金战和困境

Destined Failure:The Sunk Costs and the Dilemma of War and Peace in the Southern Song Dynasty's Interaction with the Jin Dynasty

自开禧伐金失败到端平元年宋蒙联军亡金的28年中南宋的对金政策是战略决策反复自我否定的经典案例。前景理论中的沉没成本学说假定前期投入的成本将干扰决策者的风险认知,继而影响后继政策的发展。然而,尽管南宋在宋金关系中付出的惨痛代价构成了其决策集团的沉没成本,但这些成本未能促使南宋采取坚定的北伐政策。鉴于既有研究的解释力不足,需要对沉没成本假定进行修正:决策者对于沉没成本的敏感度存在差异,决策集团内部还存在着沉没成本的类型差异。敏感度与类型的差异造成的沉没成本竞争和排序使得共同沉没成本效应复杂化。此时,即便决策集团存在共同沉没成本,也可能受其他沉没成本影响而产生严重的内部分歧。修正后的假定在很大程度上解释了南宋决策集团在伐金问题上的犹豫和反复:君主、权相和士大夫集团都受到对金交往屈辱历史的深刻影响,但他们在伐金还是和金的路线选择上存在着明显的敏感度差异,国内政治造成的普遍不安全感作为其他类型的沉没成本干扰着决策集团达成共识。最终,政治上的内讧使南宋丧失了最后的战略机遇期,未能坚定选择伐金与和金两种选项中的任意一项。

From the failure of the Kaixi campaign to the collapse of the Song Mongolian coalition in the first year of the Duanping era,the Southern Song Dynasty's policy towards Jin in the past 28 years was a classic case of repeated self-negating in strategic decision-making.The sunk cost theory in prospect theory assumes that the cost of initial investment will interfere with decision-makers'risk perception,thereby affecting the development of subsequent policies.However,although the painful costs paid by the Southern Song Dynasty in the Song-Jin relationship constituted the sunk costs of its decision-making group,these costs failed to prompt the Southern Song Dynasty to adopt a firm Northern Expedition policy.The explanatory power of the existing research is insufficient,and we need to revise them:there are differences in the sensitivity of decision-makers to sunk costs,and there are also differences in the types of sunk costs within the decision-making group.The competition and ranking of sunk costs caused by sensitivity and type differences lead to the complexity of common sunk cost effects.At this point,even if the decision-making group has common sunk costs,it may be affected by other sunk costs and generate serious internal disagreements.The new assumption largely explains the hesitation and repetition of the Southern Song Dynasty's decision-making group on the issue of the war with Jin Dynasty:the monarch,the prime minister,and the Scholar-Bureaucrat group were all deeply influenced by the humiliating history of their interactions with the Jin dynasty,but they had a clear sensitivity difference in choosing the diplomatic route with Jin dynasty,namely,whether to attack or keep the peace.The general sense of insecurity caused by domestic politics,as other types of sunk costs,interfered with the consensus reached by the decision-making group.Finally,the political infighting caused the Southern Song Dynasty to lose its final period of strategic opportunity and fail to make a firm choice between attacking and maintaining peace.