1。模型的建立 本文考虑一个由上游多个供应商和下游多个制造商构成的两层供应链结构,每次随机从供应商群体中和制造商群体中各选出一名配对,进行减排博弈供应商和制造商是有限理性的,很难在一次决策中做出最优选择,他们考虑长期合作,通过不断调整和改进策略直到达到演化稳定为止在原有生产销售体系的基础上,供应商(S)和制造商(M)的行为策略空间为(进行碳减排投入,不进行碳减排投入,简记为D,N)供应商的碳减排投入包括低碳技术研发、原材料生产工艺低碳化、原材料运输和流通高效低碳环保等;制造商的碳减排投入包括低碳技术研发、产品生产加工工艺改进、产品运输和流通高效低碳环保等假设如下: Thispaperconsidersatwotiersupplychainstructurecomposedofmultipleupstreamsuppliersandmultipledownstreammanufacturers。Eachtimeapairisrandomlyselectedfromthesuppliergroupandthemanufacturergrouptoconducttheemissionreductiongame。Suppliersandmanufacturersareboundedrationally,anditisdifficulttomakethebestchoiceinadecision。Theyconsiderlongtermcooperationandcontinuouslyadjustandimprovetheirstrategiesuntiltheyreachevolutionarystability。Onthebasisoftheoriginalproductionandsalessystem,thebehavioralstrategyspaceofthesupplier(S)andthemanufacturer(M)is(toinvestincarbonemissionreduction,nottoinvestincarbonemissionreduction,abbreviatedasD,N)。Supplierscarbonemissionreductioninvestmentincludeslowcarbontechnologyresearchanddevelopment,lowcarbonproductionprocessofrawmaterials,rawmaterialtransportationandcirculation,highefficiency,lowcarbonandenvironmentalprotection,etc。;manufacturerscarbonemissionreductioninvestmentincludeslowcarbontechnologyresearchanddevelopment,productproductionandprocessingtechnologyimprovement,producttransportationAndthecirculationofhighefficiency,lowcarbonandenvironmentalprotection。Assumeasfollows: 学习笔记:碳足迹什么意思?指一个人的能源意识和行为对自然界产生的影响,简单的将就是指个人或企业碳耗用量。 Studynotes:Whatdoescarbonfootprintmean?Referstotheimpactofapersonsenergyawarenessandbehavioronthenaturalworld,simplyreferstothecarbonconsumptionofaninpidualoracompany。 根据上文的假设,建立博弈的支付矩阵,如表1所示。 2。演化博弈模型的求解 2。1演化过程的平衡点 假设在供应商群体中,采取进行碳减排投入策略的比例为x(0x1),则采取不进行碳减排投入策略的比例为1x;同时,假设在制造商群体中,采取进行碳减排投入策略的比例为y,则采取不进行碳减排投入策略的比例为1y Assumingthatinthesuppliergroup,theproportionofcarbonemissionreductioninvestmentstrategiesadoptedisx(0x1),thentheproportionofthenocarbonemissionreductioninvestmentstrategyis1x;atthesametime,assumingthatthemanufacturerInthegroup,theproportionofthestrategyofinvestmentincarbonemissionreductionisy,andtheproportionofthestrategyofnoinvestmentincarbonemissionreductionis1y。 对于供应商来说,选择进行碳减排投入策略的期望收益为: Forsuppliers,theexpectedbenefitsofchoosingtheinvestmentincarbonemissionreductionstrategyare: 平均期望收益为: Theaverageexpectedreturnis: 对于制造商来说,选择进行碳减排投入和不进行碳减排投入策略的期望收益和平均得益分别为: Formanufacturers,theexpectedandaveragebenefitsofchoosingthestrategiesofinvestingincarbonemissionreductionandnotinvestingincarbonemissionreductionareasfollows: 根据演化博弈的复制动态公式,可以得到供应商A的复制动态方程: Accordingtothereplicationdynamicformulaoftheevolutionarygame,thereplicationdynamicequationofsupplierAcanbeobtained: 同理,制造商B的复制动态方程: Inthesameway,thecopydynamicequationofmanufacturerB: 由微分方程(7)和(8)可得一个二维动力系统(I): Fromthedifferentialequations(7)and(8),atwodimensionaldynamicsystem(I)canbeobtained: 2。2平衡点的稳定性分析 根据Friedman提出的计算微分方程组构成动态系统的群体动态,其平衡点的稳定性分析可以通过分析该系统的Jaconbian矩阵的局部稳定性得到。对微分方程组(9)依次求关于x和y的偏导数,可得出Jaconbian矩阵为: AccordingtoFriedmanscalculationofdifferentialequationstoformthegroupdynamicsofadynamicsystem,thestabilityanalysisofitsequilibriumpointcanbeobtainedbyanalyzingthelocalstabilityoftheJaconbianmatrixofthesystem。Forthesystemofdifferentialequations(9),thepartialderivativeswithrespecttoxandyaresequentiallycalculated,andtheJaconbianmatrixcanbeobtainedas: 其中: 如果以下条件得到满足: Ifthefollowingconditionsaremet: 复制动态方程的平衡点就是(渐近)局稳定的,该平衡点就是演化稳定策略为(ESS) Theequilibriumpointofthereplicationdynamicequationis(asymptotically)locallystable,andtheequilibriumpointistheevolutionarystabilitystrategy(ESS)。 命题2当0、1、0和1所在区间发生变化时,演化稳定策略也将发生改变 Proposition2Whentheintervalof0,1,0and1changes。Atthetimeoftransformation,theevolutionarystabilitystrategywillalsochange。 证明根据上述判断方法,可得出Jaconbian矩阵J在各个平衡点的迹的值和行列式的值,并判断其局部稳定性。 ProofAccordingtotheabovejudgmentmethod,thetracevalueanddeterminantvalueoftheJaconbianmatrixJateachequilibriumpointcanbeobtained,anditslocalstabilitycanbejudged。 2。3演化结果分析 由命题2可以得到供应商A和制造商B在五种情况下演化博弈过程,它们的演化相位图如图1所示 FromProposition2,wecangettheevolutionarygameprocessofsupplierAandmanufacturerBinfivesituations,andtheirevolutionphasediagramisshowninFigure1。 由以上系统动态演化相位图,可以得到如下的分析结果: Fromtheabovesystemdynamicevolutionphasediagram,thefollowinganalysisresultscanbeobtained: 参数变化对第四种情况下系统演化稳定均衡结果的影响 学习笔记:该部分分析第四种情况下的系统演化稳定分析,是因为第四种情况为制造商和供应商只有一个进行碳减排投入,存在搭便车行为,所以作者单独分析了这两种情况。 Studynotes:Thispartanalyzesthesystemevolutionandstabilityanalysisinthefourthcase。Thereasonisthatinthefourthcase,thereisonlyonecarbonemissionreductioninvestmentbythemanufacturerandthesupplier,andthereisfreeridingbehavior,sotheauthorseparatelyanalyzedthesetwocondition。 通过分析影响区域或区域的面积的因素即可转化为分析影响第四种情况下系统演化稳定策略的因素。 以分析区域的面积为例,经计算可知系统收敛于均衡点(0,1)的概率为: ByanalyzingthefactorsthataffecttheareaofareaIorareaII,itcanbetransformedintoananalysisofthefactorsthataffectthesystemevolutionandstabilitystrategyinthefourthcase。 TakingtheareaofanalysisareaIIasanexample,thecalculationshowsthattheprobabilitythatthesystemconvergestotheequilibriumpoint(0,1)is: 由该等式,可得到以下命题: 分析可知:当其他因素一定时,供应商的碳减排投入收益比0和1越小而制造商投入收益比0和1越大,系统收敛于均衡点(0,1)的概率就越大,即供应商不进行碳减排投入,制造商进行碳减排投入的概率越大;反之,当其他因素一定时,供应商的投入收益比0和1越大,制造商投入收益比0和1越小,系统收敛于均衡点(0,1)的概率就越小,即供应商不进行碳减排投入,制造商进行碳减排投入的概率就越小。 Theanalysisshowsthatwhenotherfactorsareconstant,thesmallerthesupplierscarbonemissionreductioninputincomeratio0and1,andthemanufacturersinputincomeratio0and1,thegreatertheprobabilitythatthesystemwillconvergetotheequilibriumpoint(0,1),Thatis,ifthesupplierdoesnotinvestincarbonemissionreduction,conversely,whenotherfactorsarefixed,thesupplier’sinputtorevenueratio0and1isgreater,andthemanufacturer’sinputtoreturnratio0andThesmallerthe1,thesmallertheprobabilitythatthesystemwillconvergetotheequilibriumpoint(0,1),thatis,ifthesupplierdoesnotinvestincarbonemissionreduction,thelesslikelythemanufacturerwillinvestincarbonemissionreduction。 分析可知:当其他因素一定时,供应商选择不进行碳减排投入的收益VS越小,制造商选择不进行碳减排投入的收益VM越大,系统收敛于均衡点(0,1)的概率就越大,即供应商不进行碳减排投入而制造商进行碳减排投入的概率越大;反之,当其他因素一定时,VS越大,VM越小,则供应商进行碳减排投入而制造商不进行碳减排投入的概率就越大。 Theanalysisshowsthatwhenotherfactorsareconstant,thesmallertherevenueVSofthesupplierwhochoosesnottoinvestincarbonemissionreduction,thelargertheprofitVMofthemanufacturerwhochoosesnottoinvestincarbonemissionreduction,andthesystemconvergestotheequilibriumpoint(0,1)。Thegreatertheprobability,thatis,conversely,whenotherfactorsarefixed,thegreatertheVSandthesmallertheVM,thesupplierwillreducecarbonemissionsThegreatertheprobabilitythatthemanufacturerwillnotinvestincarbonemissionsreduction。 分析可知:当其他因素一定时,供应商采取搭便车行为获得的收益S越大,制造商采取搭便车行为所获得的收益M越小,则系统收敛于均衡点(0,1)的概率就越大,供应商不进行碳减排投入而制造商进行碳减排投入的概率越大;反之,当其他因素一定时,S越小,M越大,则供应商进行碳减排投入而制造商不进行碳减排投入的概率越大。 Theanalysisshowsthatwhenotherfactorsareconstant,thegreatertheprofitSobtainedbythesupplier’sfreeridingbehavior,thesmallertheprofitMobtainedbythemanufacturer’sfreeridingbehavior,andthesystemconvergestotheequilibriumpoint(0,1),conversely,whenotherfactorsareconstant,thesmallerSandthegreaterM,thesupplierwillreducecarbonemissions。Thegreatertheprobabilitythatthemanufacturerdoesnotinvestincarbonemissionsreduction。