关系行为机制模型研究(发展经济学-中国科学院研究生

区域可持续发展与人地关系行为机制模型研究石敏俊筑波大学区域可持续发展与人地关系行为机制模型研究•区域可持续发展与农业环境政策•人地关系行为机制模型框架的建立：外部社会经济因素影响人地关系变化的机制•鄂尔多斯高原：人地关系行为机制模型与退耕还林对水土保持影响的比较静态模拟•自然科学与社会科学相融合的必要性区域可持续发展与农业环境政策•欧美国家的农业环境政策–石油农业的化肥农药高投入导致水质污染等环境问题–价格支持政策导致农产品过剩–农业环境政策的核心是推行农业粗放化经营，减少化肥农药投入，减少农产品产量–对于实行粗放经营的农户给予政策补贴发展中国家的农业环境问题•土地退化引起的农业环境问题–沙漠化，水土流失，盐碱化•环境负荷引起的农业环境问题–水质污染，土壤污染•土地退化的人为因素–人口压力，农业技术水平•依赖资源投入的静态增长导致农业粗放再生产和土地利用的平面扩张，土地利用超过环境容量时带来土地退化发展中国家的农业可持续发展•解决土地退化问题的出路在于发展可持续集约农业–可持续集约农业：通过集约化达到可持续•集约化：对少量土地实行集约经营，技术密集投入，提高单位土地面积生产力水平，为大面积退化土地休生养息恢复生态、实现区域可持续发展提供条件保护环境与发展经济的关系发展中国家的农业环境政策•解决土地退化问题的农业环境政策应当结合发展可持续集约农业来展开•发展可持续集约农业的关键是技术进步，开发实用适用技术–实用：实际农业活动中可应用的技术–适用：适合当地条件适合当地农户采用的技术•发展集约化（技术进步和技术推广）的政策补贴可作为环境保护投资进入环境经济核算人地关系行为机制模型框架：社会经济因素影响人地关系变化的机制•影响人地关系和环境生态变化的社会经济因素–人口增长–市场和价格变动–技术进步–制度和政策–收入和消费期望•单一或综合的因果关系分析不能阐明社会经济因素影响人地关系变化的机制ResourceEnvironmentLandUseAgriculturalActivityInstitutionPolicyTechnologyMarketPriceResourceConstraintImpactonEnvironmentPopulationgrowth外部社会经济环境与人地关系变化Literaturereview•Farmhouseholddecisionsonlanduseactivitiesandtechnologicalchoiceaffectthesoilqualityandthereforeplayanimportantroleinaggravatingorreducinglanddegradationprocess.•Farmhouseholddecisionsaredependentonrelativepricesofoutput,inputandproductionfactors,andothersocio-economiccircumstancesthatareinfluencedbymacroeconomicandagriculturalpolicy.•Agriculturalpoliciesaffectsoildegradationbyinfluencingthelevelofoutput,inputandfactorprices(Heerink,2001).社会经济因素影响环境变化的机制•政策和制度——外部社会经济环境——农户经济行为——资源环境变化•反馈：资源环境变化——农户经济行为（资源环境退化对经济福利的影响，现在价值与将来价值的关系）•外部社会经济环境变化：价格变动，技术进步，资金和信用约束•政策和制度：经济政策和环境政策，资源分配和资源利用秩序ConceptualframeworkPolicyreformSocio-economicenvironmentHouseholddecisionLanddegradationMacroandRegionalModelsHouseholdandVillageModelsBio-economicModelsBio-economichouseholdModelBio-economicvillageModelapproach•Econometricestimationapproach:–Lackofconsistentdata,especiallylongtimeseriesdataabouteffectofsoildegradation;–Difficulttoderivefunctionformofthereduced-formequation.•Metamodeling(Decisionrule)approach:–Estimateastatisticalrelationshipbetweenexogenousandrelevantendogenousvariables;refertoablack-boxrepresentationofrelationshipbetweenexogenousandendogenousvariables;Bio-economicvillageModel-continue•Mathematicalprogrammingapproach:–AmajoradvantageofLPModelisthatcancombineeconomicbehaviorandbiophysicalprocessinanintegratedframework.–Leontiefinput-outputcoefficientspermitsthecombinationofincompatibleeconomicandbiophysicalproductionfunction.–AdisadvantageofLPModelisthatmaygeneratevastamountof‘what-if’resultsifsomeofparametersofthemodelarenotknownwithgreataccuracy.鄂尔多斯高原人地关系行为机制模型•Bio-economicvillageLPModel–Short-termanalysis:oneyearduetouncertainty–Villagemodel:appreciatelevelofanalysis–Objectivefunction：maximizingbenefitofhouseholds–Productionfunction：Leontiefinput-outputcoefficients–Consumptionfunction：consumptionchoicebaseduponnutritionandpricesunderconstraintsofbasicnutritionintakedemandandhobby–Soilconservationprocess：convertedlandsupply–Feedbackofsoilerosiontoproduction：nofeedbackprocessBio-economicvillageLPModel)1(1111111tTtktMmNnKkktntntmtmtivtniivtvtvttvtvtVvvticgtCcniicgtcgtGgcgttcgtctcgtrhwzwzwxescxypLxescxypAU(1)s.t.CcGgcgAA(2)nmfhzzzZ(3)KkkffhzZ(4)cgggggcgxclrfslstss,,,,,CcGgcgsS(5)(6)VariabledefinitionU:householddiscountedutilityt:periodc:cropg:landtypeA:landendowmentcgtA:theareaofcropcproducedonlandtypeginperiodtp:theperunitpriceofcroporlivestockoutputy:theyieldfunctionforproductionofcropcorlivestockvx:avectorofinputsusedinproductionofcropcorlivestockve:theperunitinputpriceforinputxVariabledefinition-continuecys:thecroporlivestockoutputusedforself-consumption:thecroporlivestockoutputyusedforself-supply,suchasfodder,draftanimalL:theproductionofunitsoflivestockatperiodtvv:livestockw:thewagelevel,suchasseasonaloff-farmwagemw,constantoff-farmwagenwhiringlaborwagekwz:theoff-farmlaborsupplyofseasonalpart-timelabororconstantoff-farmlaborh:thehiringlaborsupplyhZ:familylaborfz:familylaborinputforfarmactivitiesfZ:totallaborinputforfarmactivitiesr:discountrateModulesofLPModel•Processes(73)–Production(22):croppingcorrespondingtolandtypeCorn,Millet,Potato,Sunflower,Rapeseed,Beans,Goat,Sheep,Hog,Cattle–Sale(11):Corn,Millet,Potato,Sunflower,Rapeseed,Goat,Sheep,Hog,Mutton,Pork,Wool–Self-consumption(6):Corn,Millet,Potato,Beans,Mutton,Pork–Purchase(11):Wheat,Rice,Pork,Mutton,Beef,Vegetable,Fertilizers,Pesticide,seeds,Coal–Self-supply(5):Seeds,Fodder,Manure,Firewood–Resourcesupply(17):Landsupply(6),Laborsupply(11)–Landdegradation(1):SoilerosionModulesofLPModel-continue•Constraints(70)–Products(12):–Resources(30):landconstraints(7);labortimeconstraints(13);laborallocationconstraints(10):familylabor(3),hiringlabor(7)–Balance(25):Nutritionandhumandemand(10);Farminginput(11);Livestockinput(4)–Rotation(2)–Soilerosion(1)LanduseinGe-zhen-yanVillage,Zhunger,InnerMongoliaThepolicymeasureofconvertingslopefieldintoforestandpasturestartedSince2000,withsubsidyof100kggrainand20Yuanfood-forworkper6.7aCroppingsys