Athirdcharcteristicofsharecontractsisthattherentalpercentagemayvaryamongdifferentcropsinonecontract（seesamplee）.Asisimpliedbythetheoryofsharetenancy,therentalpercentageisdependentuponthecostoftenantinputsandtherelativefertilityofland.Sincedifferentcropsusuallyrequiredifferentratiosoftenantinputstoland,thesharingpercentagesfordifferentcropsshouldbeexpectedtodifferwithinasinglecontract.Butanysetofdifferentrentalpercentagesfordifferentcropscanalsobeexpressedintermsofasingle（weightedtimeaverage）rentalpercentage,uniformforallcrops,toyieldthesamepresentvalueoftherentalreturn.Itappearsthatthelatteroptionofauniformrentalpercentage（seecontractsampled）wouldbemoreconvenient.However,ifatenantissubjecttodismissalatanytimeintheeventofpoorperformance,theuseofoneuniformrentalpercentageforcropsharvestedatdifferentseasonswouldbelikelytoleadtodisputesorrenegotiationshouldtenancydismissalbeineffect.Weusuallyfindauniformrentalpercentagebeingusedinashareleasewithspecifiedduration,andthat,whenmultiplepercentagesarefoundinaleasewithindefiniteduration,auniformpercentageisusuallyusedfordifferentcropsharvestedinthesameseason（seecontractsamplee）.
Wemaysummarizethecharacteristicsofsharecontractsbyquotingtheobservationmadebytwowriters-whowerecriticaloftenantfarminginChina:
Underthesystemofsharerent,theyieldsaftereachharvestaretobesharedaccordingtocertainmutuallystipulatedpercentagesbetweenthelandownerandthetenant.Withtheexceptionofsomelandusedforfarmsteadpurposes,thetenantisrequiredtocultivatealmostalltheassignedfieldsfortheproductionofcrops.Sometimes,thetenantisevenrequiredtofurnishfarmingequipment……andotherexpenses.Thelandownerandthetenantmutuallydecidetheareatobeusedforeachcrop……Besidestheabove,theonlyaffairofmanagementoverwhichthelandownerexercisescontrolisconfinedtopermanentimprovementsoflandassets.Thislastcharacteristicisidenticalwithfixed-rentcontracts.[16]
[1].SeeJ.L.Buck,FarmOwnershipandTenancyinChina（Shanghai:NationalChristianCouncil,1927）.
[2].NationalGovernment,StatisticsDepartment,StatisticalAnalysisofTenancySystemsinChina（China:ChengChungBookStore,1942）,pp.52-53.
[3].Pe-YuChangandYin-YuenWang,QuestionsofFarmTenancyinChina（Chungking:CommercialPress,1943）,p.68.
[4].NationalGovernment,StatisticalAnalysis,pp.54-55.
[5].Seeibid.,pp.53-54；andChangandWang,QuestionsofFarmTenancy,pp.67-70.
[6].DepartmentofRealEstates,ChinaEconomicYearbook（China,1936）,pp.G62-83.
[7].ExecutiveYuan,ChangesinLandRights（China,1942）,no.2.Thedatawereobtainedfromsamplecontractsinfourteenprovincesin1938.
[8].Unfortunately,Ihavenotbeenabletofinddatathatwouldconfirmorrefutethisstatement.
[9].Notethatwithasharecontractthelandownernotonlysharesthepossiblelossinabadyear,butalsothegainofagoodharvestwhichwillreducetheriskpremiumbyafraction.
[10].SeetheUniversityofNanking,RentalSystemsinFourProvinces（Nanking,1936）,pp.65-67.
[11].NationalGovernment,StatisticalAnalysis,pp.54-55.
[12].ChangandWang,QuestionsofFarmTenancy,p.63.
[13].Ibid.,pp.63-64.
[14].Samplesharecontractshadnotbeenavailabletomewhenchapter2waswritten.WhenIpredictedthat,accordingtoeconomictheory,tenantinputsarestipulatedinasharecontract,Ididnotmentionthestipulationofmultiplecropplantationsbecauseonlyonemutuallyagreedproductwasassumed.
[15].J.L.Buck,ChineseFarmEconomy（Chicago:UniversityofChicagoPress,1930）,pp.149-50.
[16].ChangandWang,QuestionsofFarmTenancy,p.49.ForsimilarobservationsseeChing-MohChen,LandRentsofVariousProvincesinChina（Shanghai:CommercialPress,1936）；Chi-MingChiao,ASocialandEconomicStudyofFarmVillagesinChina（Nanking:UniversityofNanking,1938）,chap.9；andChinaEconomicResearchDepartment,SourceMaterialsofRecentChineseAgriculturalHistory,1912-27（Peking:UnitedBookStore,1957）,pp.89-95.
C.TheDurationofLeaseContracts
AninvestigationconductedinChina（1934）,coveringatotalofninety-threeprefecturesineightprovinces,showsthatthedis-tributionofleasedurationswasasfollows:29percentofthetenantcontractswereindefinite（thatis,unspecifiedandusuallyterminableaftereveryharvest）,25percentannualleases,27per-centfromthreetotenyears,8percentfromtentotwentyyears,and11percentwereperpetualleases.[1]Twothingsshouldbenoted.First,astipulatedleasedurationmeansonlythattenancymaynotbeterminatedaslongasthecontractedtermsareful-filledbyeachparty.Thatthedurationoftheleaseisspecifieddoesnotprohibitmutualrenegotiationswithintheleaseduration.Second,asthefrequencyofshort-termleaseshasbeenusedtoillustratetheturnoverrateoftenancy,itshouldbepointedoutthatleaseterminationisnotthesameastenancydismissal.Availabledatarevealthatthefrequencyoftenancydismissalwasnothigh.[2]
Intheliteratureonlandtenure,twoargumentshavebeenmonlyusedinsupportoftheallegedinefficiencyofleasedurationsoflessthantenyears.[3]Oneofthemclaimsthatshortdurationsimposeinsecurityonthetenantandthusimpairhisincentivetofarm.Butinsecurity,althoughundesirableforthetenant,mayprovideastimulustofarmingactivity.[4]Anotherargumentisthattheshort-termleasediscouragesinvestmentinland.Butthisisrefutedbythefactthatyieldsperacreontenantfarmsarenotlowerthanonownerfarms;norhasanyevidencebeenofferedtoshowthat,inChina,productivityundertenancyvarieswiththedurationofaleasingcontract.