<span style="; FONT-FAMILY: 宋体;"></span><span lang="EN-US" style=";"><p><span style="; FONT-FAMILY: 宋体;"></span><span lang="EN-US" style=";"><p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman";">证明：如果两个厂商有向上倾斜的反应函数，从而</span><span lang="EN-US" style=";"><font face="Times New Roman">f</font></span><span style="; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体;">ˊ</span><sub><span lang="EN-US" style=";"><font face="Times New Roman">i</font></span></sub><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman";">（</span><span lang="EN-US" style=";"><font face="Times New Roman">y<sub>i</sub></font></span><span lang="EN-US" style="; FONT-FAMILY: 宋体;">)</span><span style="; FONT-FAMILY: 宋体;">＞<span lang="EN-US">0,(y<sub>1</sub><sup>*</sup>,y<sub>2</sub><sup>*</sup>)</span>为斯塔伯格均衡，则<span lang="EN-US">f<sub>2</sub>(f<sub>1</sub>(y<sub>2</sub><sup>*</sup>))</span>＞<span lang="EN-US">f<sub>2</sub>(y<sub>1</sub><sup>*</sup>)=y<sub>2</sub><sup>*</sup></span>。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="; FONT-FAMILY: 宋体;"></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="; FONT-FAMILY: 宋体;">范里安《微观经济学（高级教程）》第三版331页16.5题。</span><span lang="EN-US" style=";"><p></p></span></p></p></span></p></span>