Furthermore，arelativelyinferiorsoilwhichisnewlycultivatedandneverbeforetouchedbycivilisationprovidedtheclimaticconditionsarethennotcompletelyunfavourable，hasaccumulatedagreatdealofplantfoodthatiseasilyassimilated-atleastintheupperlayersofthesoil-sothatitwillyieldcropsforalongtimewithouttheapplicationoffertilisersandevenwithverysuperficialcultivation。ThewesternprairieshavetheadditionaladvantageofhardlyrequiringanyclearingexpensessinceNaturehasmadethemarable。[33a]Inlessfertileareasofthiskind，thesurplusisnotproducedasaresultofthehighfertilityofthesoil，i。e。，theyieldperacre，butasaresultofthelargeacreagewhichmaybesuperficiallycultivated，sincesuchlandcoststhecultivatornothing，ornexttonothingascomparedwitholdercountries。Thisisthecase，forinstance，wheresharecroppingexists，asinpartsofNewYork，Michigan，Canada，etc。Afamilysuperficiallycultivates，say，100acres，andalthoughtheoutputperacreisnotlarge，theoutputfrom100acresyieldsaconsiderablesurplusforsale。Inadditiontothis，cattlemaybegrazedonnaturalpasturesatalmostnocost，withoutrequiringartificialgrassmeadows。Itisthequantityoftheland，notitsquality，whichisdecisivehere。ThepossibilityofsuchsuperficialcultivationIisnaturallymoreorlessrapidlyexhausted，namely，ininverseproportiontothefertilityofthenewsoilandindirectproportiontotheexportofitsproducts。”Andyetsuchacountrywillgiveexcellentfirstcrops，evenofwheat，andwillsupplytothosewhoskimthefirstcreamoffthecountry，alargesurplusofthisgraintosendtomarket”
1，c。，p。224。Propertyrelationsincountrieswithmaturercivilisations，withtheirdeterminationofthepriceofuncultivatedsoilbythatofthecultivated，etc。，makesuchanextensiveeconomyimpossible。
Thatthissoil，therefore，neednotbeexceedinglyrich，asRicardoimagines，northatsoilsofequalfertilityneedbecultivated，maybeseenfromthefollowing。IntheStateofMichigan465，900acreswereplantedin1848towheatwhichyielded4，739，300bushels，oranaverageof101/
bushelsperacreafterdeductingseedgrain，thisleaveslessthan9bushelsperacre。Ofthe29countiesofthisState，2producedanaverageof7
bushels，3anaverageof8bushels，2——9，7——10，6——11，3——12，4——13bushels，andonlyonecountyproducedanaverageof16bushels，andanother18bushelsperacrel。c。，p。225。
Forpracticalcultivationhighersoilfertilitycoincideswithgreatercapabilityofimmediateexploitationofsuchfertility。Thelattermaybegreaterinanaturallypoorsoilthaninanaturallyrichone；butitisthekindofsoilwhichacolonistwilltakeupfirst，andmusttakeupwhencapitaliswanting。
Finally，theextensionofcultivationtolargerareas-asidefromthecasejustmentioned，inwhichrecoursemustbehadtosoilinferiorthanthatcultivatedhitherto-tothevariouskindsofsoilfromAtoD，thus，forinstance，thecultivationoflargertractsofBandCdoesnotbyanymeanspresupposeapreviousriseingrainpricesanymorethantheprecedingannualexpansionofcottonspinning，forinstance，requiresaconstantriseinyarnprices。Althoughconsiderableriseorfallinmarket-pricesaffectsthevolumeofproduction，regardlessofitthereisinagriculturejustasinallothercapitalisticallyoperatedlinesofproductionneverthelessacontinuousrelativeover-production，initselfidenticalwithaccumulation，evenatthoseaveragepriceswhoselevelhasneitheraretardingnorexceptionallystimulatingeffectonproduction。Underothermodesofproductionthisrelativeoverproductioniseffecteddirectlybythepopulationincrease，andincoloniesbysteadyimmigration。Thedemandincreasesconstantly，and，inanticipationofthisnewcapitaliscontinuallyinvestedinnewland，althoughthisvarieswiththecircumstancesfordifferentagriculturalproducts。Itistheformationofnewcapitalswhichinitselfbringsthisabout。Butsofarastheindividualcapitalistisconcerned，hemeasuresthevolumeofhisproductionbythatofhisavailablecapital，totheextentthathecanstillcontrolithimself。Hisaimistocaptureasbigaportionaspossibleofthemarket。Shouldtherebeanyover-production，hewillnottaketheblameuponhimself，butplacesituponhiscompetitors。Theindividualcapitalistmayexpandhisproductionbyappropriatingalargeraliquotshareoftheexistingmarketorbyexpandingthemarketitself。
33a[ItispreciselytherapidlygrowIngcultivationofsuchprairieorstepperegionswhichoflateturnstherenownedstatementofMaithus，that”thepopulationisaburdenuponthemeansofsubsistence，”intoridicule，andproducedinitssteadtheagrarianlamentthatagriculture，andwithitGermany，willberuined，unlessthemeansofsubsistencewhichareaburdenuponthepopulationareforciblykeptawayfromthem。Thecultivationofthesesteppes，prairies，pampas，ilanos，etc。，isneverthelessonlyinitsbeginning；
itsrevolutionisingeffectonEuropeanagriculturewill，therefore，makeitselffeltinthefutureevenmoresothanhitherto-F。E。
Capital，Vol。3，Chapter40KarlMarxCAPITALVol。III
THEPROCESSOF
CAPITALISTPRODUCTIONASAWHOLEPartVI
TRANSFORMATIONOFSURPLUS-PROFIT
INTOGROUNDRENTCHAPTER40
SecondFormofDifferentialRentDifferentialRentII
Thusfarwehaveconsidereddifferentialrentonlyastheresultofvaryingproductivityofequalamountsofcapitalinvestedinequalareasoflandofdifferentfertility，sothatdifferentialrentwasdeterminedbythedifferencebetweentheyieldfromthecapitalinvestedintheworst，rentlesssoilandthatfromthecapitalinvestedinsuperiorsoil。Wehadsidebysidecapitalsinvestedindifferentplotsofland，sothateverynewinvestmentofcapitalsignifiedamoreextensivecultivationofthesoil，anexpansionofcultivatedarea。Inthelastanalysis，however，differentialrentwasbyitsnaturemerelytheresultofthedifferentproductivityofequalcapitalsinvestedinland。Butcanitmakeanydifferenceifcapitalsofdifferentproductivityareinvestedsuccessivelyinthesameplotoflandorsidebysideindifferentplotsofland，providedtheresultsarethesame？
Tobeginwith，thereisnodenyingthat，insofarastheformationofsurplus-profitisconcerned，itisimmaterialwhether£；3inproductionpriceperacreofAyield1qr，sothat£；3isthepriceofproductionandtheregulatingmarket-priceof1qr，while£；3inproductionpriceperacreofByield2qrs，andthereby£；3ofsurplus-profit，similarly，£；3inproductionpriceperacreofCyield3qrsand£；6ofsurplus-profit，and，finally，£；3inproductionpriceperacreofDyield4qrsand£；9ofsurplus-profit；orwhetherthesameresultisachievedbyapplyingthese£；12inproductionprice，or£；10
ofcapital，withthesamesuccessinthesamesequenceupononeandthesameacre。Itisinbothcasesacapitalof£；10，whosevalueportionsof£；21/2eacharesuccessivelyinvested——whetherinfouracresofvaryingfertilitysidebyside，orsuccessivelyinoneandthesameacreofland——andbecauseoftheirvaryingoutputs，oneportionyieldsnosurplus-profit，whereastheotherportionsyieldsurplus-profitproportionatetotheirdifferenceinyieldwithrespecttorentlessinvestment。
Thesurplus-profitandthevariousratesofsurplus-profitforthedifferentvalueportionsofcapitalareformedinthesamemannerinbothcases。
Andtherentisnothingbutaformofthissurplus-profit，whichconstitutesitssubstance。Butatanyrate，inthesecondmethod，therearesomedifficultiesconcerningthetransformationofsurplus-profitintorent，thischangeofform，whichincludesthetransferofsurplus-profitfromthecapitalisttenanttothelandowner。ThisaccountsfortheobstinateresistanceofEnglishtenantstoofficialagriculturalstatistics。AnditaccountsfortheirstruggleagainstthelandlordsoverthedeterminationofactualresultsderivedfromtheircapitalinvestmentMorton。Forrentisfixedwhenlandisleased，andafterthatthesurplus-profitarisingfromsuccessiveinvestmentsofcapitalflowsintothepocketsofthetenantaslongastheleaselasts。Thisiswhythetenantshavefoughtforlongleases，and，ontheotherhand，duetothegreaterpowerofthelandlords，anincreaseinthenumberoftenanciesatwillhastakenplace，i。e。，leaseswhichcanbecancelledannually。
Itisthereforeevidentfromtheveryoutsetthat，evenifimmaterialforthelawofformationofsurplus-profit，itmakesaconsiderabledifferenceforthetransformationofsurplus-profitintoground-rentwhetherequalcapitalsareinvestedsidebysideinequalareasoflandwithunequalresults，orwhethertheyareinvestedsuccessivelyinthesameland。Thelattermethodconfinesthistransformation，ontheonehand，withinnarrowerlimits，ontheotherhand，withinmorevariablelimits。Forthisreason，theworkofthetax-assessor，asMortonshowsinhisResourcesofEstates，becomesaveryimportant，complicatedanddifficultprofessionincountriespractisingintensivecultivationand，economicallyspeaking，wemeannothingmorebyintensivecultivationthantheconcentrationofcapitaluponthesameplotratherthanitsdistributionamongseveraladjoiningpiecesofland。Ifsoilimprovementsareofamorepermanentnaturetheartificiallyincreaseddifferentialfertilityofthesoilcoincideswithitsnaturaldifferentialfertilityassoonastheleaseexpires，andthereforetheassessmentoftherentcorrespondstothedeterminationoftherentonplotsofdifferentfertilitiesingeneral。Ontheotherhand，insofarastheformationofsurplus-profitisdeterminedbythemagnitudeofoperatingcapital，theamountofrentforacertainamountofoperatingcapitalisaddedtotheaveragerentofthecountryandthusprovisionismadeforthenewtenanttocommandsufficientcapitaltocontinuecultivationinthesameintensivemanner。
InthestudyofdifferentialrentII，thefollowingpointsarestilltobeemphasised。
First，itsbasisandpointofdeparture，notjusthistorically，butalsoinsofarasconcernsitsmovementsatanygivenperiodoftime，isdifferentialrentI，thatis，thesimultaneouscultivationsidebysideofSoilsofunequalfertilityandlocation；inotherwords，thesimultaneousapplication，sidebyside，ofunequalportionsofthetotalagriculturalcapitaluponplotsoflandofunequalquality。
Historicallythisisself-evident。Inthecolonies，colonistshavebutlittlecapitaltoinvest；theprincipalproductionagentsarelabourandland。Everyindividualheadoffamilyseeksforhimselfandhiskinanindependentfieldofemploymentalongsidehisfellow-colonists。Thismustgenerallybethecaseinagricultureproperevenunderpre-capitalistmodesofproduction。Inthecaseofsheep-herdingandcattle-raising，ingeneral，asindependentlinesofproduction，exploitationofthesoilismoreorlesscommonandextensivefromtheveryoutset。Thecapitalistmodeofproductionhasforitspointofdepartureformermodesofproductioninwhichthemeansofproductionwere，infactorlegally，thepropertyofthetillerhimself，inaword，fromahandicraft-likepursuitofagriculture。
Itisinthenatureofthingsthatthelattergiveswaybutgraduallytotheconcentrationofmeansofproductionandtheirtransformationintocapital，asagainstdirectproducerstransformedintowage-labourers。Insofarasthecapitalistmodeofproductionismanifestedheretypically，itoccursatfirstparticularlyinsheep-herdingandcattle-raising。Butitisthusnotmanifestedinaconcentrationofcapitaluponarelativelysmallareaofland，butinproductiononalargerscale，economisingintheexpenseofkeepinghorses，andinotherproductioncosts；but，infact，notbyinvestingmorecapitalinthesameland。Furthermore，inaccordancewiththenaturallawsoffieldhusbandry，capital——usedhere，atthesametime，inthesenseofmeansofproductionalreadyproduced——becomesthedecisiveelementinsoilcultivationwhencultivationhasreachedacertainlevelofdevelopmentandthesoilhasbeencorrespondinglyexhausted。
Solongasthetilledareaissmallincomparisonwiththeuntilled，andsolongasthesoilstrengthhasnotbeenexhaustedandthisisthecasewhencattle-raisingandmeatconsumptionprevailintheperiodbeforeagricultureproperandplantnutritionhavebecomedominant，thenewdevelopingmodeofproductionisopposedtopeasantproductionmainlyintheextensivenessofthelandbeingtilledforacapitalist，inotherwords，againintheextensiveapplicationofcapitaltolargerareasofland。ItshouldthereforeberememberedfromtheoutsetthatdifferentialrentIisthehistoricalbasiswhichservesasapointofdeparture。Ontheotherhand，themovementofdifferentialrentIIatanygivenmomentoccursonlywithinaspherewhichisitselfbutthevariegatedbasisofdifferentialrentI。
Secondly，inthedifferentialrentinformII，thedifferencesindistributionofcapitalandabilitytoobtaincreditamongtenantsareaddedtothedifferencesinfertility。Inmanufacturingproper，eachlineofbusinessrapidlydevelopsitsownminimumvolumeofbusinessandacorrespondingminimumofcapital，belowwhichnoindividualbusinesscanbeconductedsuccessfully。Inthesameway，eachlineofbusinessdevelopsanormalaverageamountofcapitalabovethisminimum，whichthebulkofproducersshould，anddo，command。Alargervolumeofcapitalcanproduceextraprofit；asmallervolumedoesnotsomuchasyieldtheaverageprofit。
Thecapitalistmodeofproductionspreadsinagriculturebutslowlyandunevenly，asmaybeobservedinEngland，theclassiclandofthecapitalistmodeofproductioninagriculture。Insofarasthefreeimportationofgraindoesnotexist，oritseffectisbutlimitedbecausethevolumeissmall，producersworkinginferiorsoil，andthusunderworsethanaverageconditionsofproduction，determinethemarket-price。Alargeportionofthetotalmassofcapitalinvestedinhusbandry，andingeneralavailabletoit，isintheirhands。
Itistruethatthepeasant，forexample，expendsmuchlabouronhissmallplotofland。Butitislabourisolatedfromobjectivesocialandmaterialconditionsofproductivity，labourrobbedandstrippedoftheseconditions。
Thiscircumstanceenablestheactualcapitalisttenantstoappropriateaportionofsurplus-profit——afactwhichwouldnotobtain，atleastsofarasthispointisconcerned，ifthecapitalistmodeofproductionwereasevenlydevelopedinagricultureasinmanufacture。
Letusfirstconsiderjusttheformationofsurplus-profitwithdifferentialrentII，withoutforthepresentbotheringabouttheconditionsunderwhichthetransformationofthissurplus-profitintoground-rentmaytakeplace。
ItisthenevidentthatdifferentialrentIIismerelydifferentlyexpresseddifferentialrentI，butidenticaltoitinsubstance。ThevariationinfertilityofvarioussoiltypesexertsitsinfluenceinthecaseofdifferentialrentIonlyinsofarasunequalresultsareattainedbycapitalsinvestedinthesoil，i。e。，theamountofproductsobtainedeitherwithrespecttoequalmagnitudesofcapital，orproportionateamounts。Whetherthisinequalitytakesplaceforvariouscapitalsinvestedsuccessivelyinthesamelandorforcapitalsinvestedinseveralplotsofdifferingsoiltype——thiscanchangenothinginthedifferenceinfertilitynorinitsproductandcanthereforechangenothingintheformationofdifferentialrentforthemoreproductivelyinvestedportionsofcapital。Itisstillthesoilwhich，nowasbefore，showsdifferentfertilitywiththesameinvestmentofcapital，savethatherethesamesoilperformsforacapitalsuccessivelyinvestedindifferentportionswhatvariouskindsofsoildointhecaseofdifferentialrentIfordifferentequalportionsofsocialcapitalinvestedinthem。
Ifthesamecapitalof£；10，whichisshowninTableItobeinvestedintheformofindependentcapitalsof£；21/2eachbyvarioustenantsineachacreofthefoursoiltypesA，B，CandD，wereinsteadsuccessivelyinvestedinoneandthesameacreD，sothatthefirstinvestmentyielded4qrs，thesecond3，thethird2，andthefourth1qrorinthereverseorder，thenthepriceofthequarterfurnishedbytheleastproductivecapital，namely=£；3，wouldnotyieldanydifferentialrent，butwoulddeterminethepriceofproduction，solongasthesupplyofwheatwhosepriceofproductionis£；3wereneeded。
Andsinceourassumptionisthatthecapitalistmodeofproductionprevails，sothatthepriceof£；3includestheaverageprofitmadebyacapitalof£；21/2generally，theotherthreeportionsof£；21/2eachwillyieldsurplus-profitinaccordancewiththedifferenceinoutput，sincethisoutputisnotsoldatitsownpriceofproduction，butatthepriceofproductionoftheleastproductiveinvestmentof£；21/2；thelatterinvestmentdoesnotyieldanyrentandthepriceofitsproductsisdeterminedbythegenerallawofpricesofproduction。Theformationofsurplus-profitwouldbethesameasinTableI。
OnceagainitisseenherethatdifferentialrentIIpresupposesdifferentialrentI。Theminimumoutputobtainedfromacapitalof£；21/2，i。e。，fromtheworstsoil，ishereassumedtobe4qr。Assumed，also，isthatasidefromthe£；21/2whichyield4qrsandforwhichhepaysadifferentialrentof3qrs，thetenantoperatingwithsoiltypeDinvestsinthissamesoil£；21/2whichyieldonly1qr，likethesamecapitalupontheworstsoilA。Thiswouldbeaninvestmentofcapitalwhichdoesnotyieldrent，sinceitreturnstohimonlyaverageprofit。Therewouldbenosurplus-profitwhichcouldbetransformedintorent。Ontheotherhand，thisdecreasingyieldofthesecondinvestmentofcapitalinDwouldhavenoinfluenceontherateofprofit。Itwouldbethesameasthough£；21/2hadbeeninvestedanewinanadditionalacreofsoiltypeA，acircumstancewhichwouldinnowayaffectthesurplus-profitand，therefore，thedifferentialrentofsoilsA，B，CandD。Butforthetenant，thisadditionalinvestmentof£；21/2inDwouldhavebeenquiteasprofitableas，inaccordancewithourassumption，theinvestmentoftheoriginal£；21/2peracreofD，althoughthelatteryields4qrs。Furthermore，iftwootherinvestmentsof£；21/2eachshouldyieldanadditionaloutputof3qrsand2qrsrespectively，adecreasewouldhavetakenplaceagaincomparedwiththeoutputfromthefirstinvestmentof£；21/2inD，whichyielded4qrs，i。e。，asurplus-profitof3qrs。Butitwouldbemerelyadecreaseintheamountofsurplus-profit，andwouldnotaffecteithertheaverageprofitortheregulatingpriceofproduction。
Thelatterwouldbethecaseonlyiftheadditionalproductionyieldingthisdecreasingsurplus-profitmadetheproductionuponAsuperfluous，andthrewacreAoutofcultivation。Insuchcase，thedecreasingproductivenessoftheadditionalinvestmentofcapitalinacreDwouldbeaccompaniedbyafallinthepriceofproduction，forinstance，from£；3to£；11/2，ifacreBwouldbecometherentlesssoilandregulatorofthemarket-price。
TheoutputfromDwouldnowbe=4132=10qrswhereasformerlyitwas=4qrs。ButthepriceperquarterasregulatedbyBwouldhavefallento£；11/2。ThedifferencebetweenDandBwouldbe=10？=8qrs，at£；11/2perquarter=£；12，whereasthemoney-rentfromDwaspreviously=£；9。Thisshouldbenoted。Calculatedperacre，themagnitudeofrentwouldhaverisenby331/3%
inspiteofthedecreasingrateofsurplus-profitonthetwoadditionalcapitalsof£；21/2each。
Weseefromthistowhathighlycomplicatedcombinationsdifferentialrentingeneral，andinformIIcoupledwithformI，inparticular，maygiverise，whereasRicardo，forinstance，treatsitveryone-sidedlyandasthoughitwereasimplematter。Asintheabovecase，afallintheregulatingmarket-priceandatthesametimeriseinrentfromfertilesoilsmaytakeplacesothatboththeabsoluteproductandtheabsolutesurplus-productincrease。IndifferentialrentI，indescendingorder，therelativesurplus-productandthustherentperacremayincrease，althoughtheabsolutesurplus-productperacreremainsconstantorevendecreases。
Butatthesametime，productivenessoftheinvestmentsofcapitalmadesuccessivelyinthesamesoildecreases，althoughalargeportionofthemfallstothemorefertilesoils。Fromacertainpointofview——asconcernsbothoutputandpricesofproduction——theproductivityoflabourhasrisen。Butfromanotherpointofview，itbasdecreasedbecausetherateofsurplus-profitandthesurplus-productperacredecreaseforthevariousinvestmentsofcapitalinthesameland。
DifferentialrentII，withdecreasingproductivenessofsuccessiveinvestmentsofcapital，wouldnecessarilybeaccompaniedbyariseinpriceofproductionandanabsolutedecreaseinproductivityonlyifinvestmentsofcapitalcouldbemadeinnonebuttheworstsoilA。IfanacreofA，whichwithaninvestmentofcapitalof£；21/2；yielded1
qratapriceofproductionof£；3，shouldonlyyieldatotalof11/2qrswithanadditionaloutlayof£；21/2，i。e。，atotalinvestmentof£；5，thenthepriceofproductionofthis11/2qrs=£；6orthatof1qr=£；4。Everydecreaseinproductivitywithagrowinginvestmentofcapitalwouldheremeanarelativedecreaseinoutputperacre，whereasuponsuperiorsoilsitwouldonlysignifyadecreaseinthesuperfluoussurplus-product。
Butbythenatureofthings，withthedevelopmentofintensivecultivation，i。e。，withsuccessiveinvestmentsofcapitalinthesamesoil，thiswilltakeplacemoreadvantageously，ortoagreaterextentonbettersoils。
Wearenotreferringtopermanentimprovementsbywhichahithertouselesssoilisconvertedintousefulsoil。Thedecreasingproductivenessofsuccessiveinvestmentsofcapitalmust，therefore，haveprincipallytheeffectindicatedabove。Thebettersoilisselectedbecauseitaffordsthebestpromisethatcapitalinvestedinitwillbeprofitable，sinceitcontainsthemostnaturalelementsoffertility，whichneedbutbeutilised。
When，aftertheabolitionoftheCornLaws，cultivationinEnglandbecamestillmoreintensive，agreatdealofformerwheatlandwasdevotedtootherpurposes，particularlycattlepastures，whilethefertilelandbestsuitedforwheatwasdrainedandotherwiseimproved。Thecapitalforwheatcultivationwasthusconcentratedinamorelimitedarea。
Inthiscase——andallpossiblesurplusratesbetweenthegreatestsurplus-productofthebestsoilandtheoutputofrentlesssoilAcoincideherewithanabsolute，ratherthanarelative，increaseinsurplus-productperacre——thenewlyformedsurplus-profitpotentialrentdoesnotrepresentaportionofaformeraverageprofittransformedintorentaportionoftheoutputinwhichtheaverageprofitformerlywasexpressedbutanadditionalsurplus-profit，whichistransformedoutofthisformintorent。
Ontheotherhand，onlyinsuchcasewherethedemandforgrainincreasedtosuchanextentthatthemarket-priceroseabovethepriceofproductionofA，sothatthesurplus-productofA，B，oranyotherkindofsoilcouldbesuppliedonlyatapricehigherthan£；3wouldthedecreaseinyieldfromanadditionalinvestmentofcapitalinanyofthesoiltypesA，B，CandDbeaccompaniedbyariseinpriceofproductionandtheregulatingmarket-price。InsofarasthislastedforalengthyperiodofLimewithoutresultinginthecultivationofadditionalsoilAofatleastthequalityofA，orwithoutacheapersupplyresultingfromothercircumstances，wageswouldriseinconsequenceoftheincreaseinthepriceofbread，everythingelsebeingequal，andtherateofprofitwouldfallaccordingly。
Inthiscase，itwouldbeimmaterial，whethertheincreaseddemandweresatisfiedbybringingundercultivationsoilofinferiorqualitythanA，orbyadditionalinvestmentsofcapital，inanyofthefourtypesofsoil。
Differentialrentwouldthenincreasetogetherwithafallingrateofprofit。
Thisonecase，inwhichthedecreasingproductivenessofsubsequentadditionalcapitalsinvestedinalreadycultivatedSoilsmayleadtoanincreaseinpriceofproduction，afallinrateofprofit，andtheformationofhigherdifferentialrent——forthelatterwouldincreaseunderthegivencircumstancesuponallkindsofsoiljustasthoughsoilofinferiorqualitythanAwereregulatingthemarket-price——hasbeenlabelledbyRicardoastheonlycase，thenormalcase——towhichhereducestheentireformationofdifferentialrentII。
ThiswouldalsobethecaseifonlytypeAsoilwerecultivatedandsuccessiveinvestmentsofcapitalinitwerenotaccompaniedbyaproportionalincreaseinproduce。
Herethen，inthecaseofdifferentialrentII，onecompletelylosessightofdifferentialrentI。
Exceptforthiscase，inwhichthesupplyfromthecultivatedsoilsiseitherinsufficientandthemarket-pricethuscontinuallyhigherthanthepriceofproductionuntilnewadditionalsoilofinferiorqualityistakenundercultivation，oruntilthetotalproductfromtheadditionalcapitalinvestedinvariouskindsofsoilcanbesuppliedonlyatahigherpriceofproductionthanthathithertoprevailing——saveforthiscase，theproportionaldropinproductivityoftheadditionalcapitalsleavestheregulatingpriceofproductionandtherateofprofitunchanged。Fortherest，threeadditionalcasesarepossible:
aIftheadditionalcapitalinvestedinanyoneofthetypesofsoilA，B，CorDyieldsonlytherateofprofitdeterminedbythepriceofproductionofA，thennosurplus-profit，andthereforenopotentialrent，isformed，anymorethantherewouldbeifadditionaltypeAsoilhadbeencultivated。
bIftheadditionalcapitalyieldsalargerproduct，newsurplus-profitpotentialrentis，ofcourse，formedprovidedtheregulatingpriceremainsthesame。Thisisnotnecessarilythecase；itisnotthecase，inparticular，whenthisadditionalproductionthrowssoilAoutofcultivationandthusoutofthesequenceofcompetingsoils。Inthiscase，theregulatingpriceofproductionfalls。Ifthiswereaccompaniedbyafallinwages，orifthecheaperproductweretoenterintotheconstantcapitalasoneofitselements，therateofprofitwouldrise。IftheincreasedproductivityoftheadditionalcapitalhadtakenplaceuponthebestsoilsCandD，itwoulddependentirelyuponthedegreeofincreasedproductivityandtheamountofadditionalnewcapitaltowhatextenttheformationofincreasedsurplus-profitandthusincreasedrentwouldbeassociatedwiththefallinpricesandtheriseintherateofprofit。Thelattermayalsorisewithoutafallinwages，throughacheapeningoftheelementsofconstantcapital。
cIftheadditionalinvestmentofcapitaltakesplacewithdecreasingsurplus-profit，butinsuchmannerthattheyieldfromtheadditionaloutlaystillleavesasurplusabovetheyieldfromthesamecapitalinvestedinA，anewformationofsurplus-profittakesplaceunderallcircumstances，unlesstheincreasedsupplyexcludessoilAfromcultivation。ThismaytakeplacesimultaneouslyuponD，C，BandA。But，ontheotherhand，iftheworstsoilAissqueezedoutofcultivation，thentheregulatingpriceofproductionfallsanditwilldependupontherelationbetweenthereducedpriceof1qrandtheincreasednumberofquartersformingsurplus-profitwhetherthesurplus-profitexpressedinmoney，andconsequentlythedifferentialrent，risesorfalls。Butatanyrate，itisnoteworthyherethatwithdecreasingsurplus-profitfromsuccessiveinvestmentsofcapitalthepriceofproductionmayfall，insteadofrising，whichitseeminglyshoulddoatfirstsight。
Theseadditionalinvestmentsofcapitalwithdecreasingsurplusyieldscorrespondentirelytothecaseinwhich，e。g。，fournewindependentcapitalsof£；21/2eachwouldbeinvestedinsoilswithfertilitybetweenAandB，BandC，CandD，andyielding11/2，21/3，22/3，and3qrsrespectively。
Surplus-profitpotentialrentwouldtakeshapeonallthesesoilsforallfouradditionalcapitals，althoughtherateofsurplus-profit，comparedwiththatforthesameinvestmentofcapitalonthecorrespondinglybettersoil，wouldhavedecreased。AnditwouldbeimmaterialwhetherthesefourcapitalswereinvestedinD，etc。，ordistributedbetweenDandA。
Wenowcometoanessentialdifferencebetweenthetwoformsofdifferentialrent。
UnderdifferentialrentI，withconstantpriceofproductionandconstantdifferences，theaveragerentperacre，ortheaveragerateofrentoncapital，mayincreasetogetherwiththerental。Buttheaverageisamereabstraction。Theactualamountofrent，calculatedperacreorwithrespecttocapital，remainsthesamehere。
Ontheotherhand，underthesameconditions，theamountofrentcalculatedperacremayincreasealthoughtherateofrent，measuredrelativetoinvestedcapital，remainsthesame。
Letusassumethatproductionisdoubledbytheinvestmentof£；5
insteadof£；21/2ineachofthesoilsA，B，CandD，i。e。，atotalof£；20insteadof£；10，andthattherelativefertilityremainsunchanged。Thiswouldbetantamounttocultivating2insteadof1acreofeachofthesekindsofsoilatthesamecost。Therateofprofitwouldremainthesame；alsoitsrelationtosurplus-profitorrent。ButifAwerenowtoyield2qrs，B——4，C——6，andD——8，thepriceofproductionwouldneverthelessremain£；3perquarterbecausethisincreaseisnotduetodoubledfertilitywiththesamecapital，buttothesameproportionalfertilitywithadoubledcapital。ThetwoquartersofAwouldnowcost£；6justas1qrcost£；3before。
Theprofitwouldhavedoubledonallfoursoils，butonlybecausetheinvestedcapitalwasdoubled。Inthesameproportion，however，therentwouldalsohavebeendoubled；itwouldbe2qrsforBinsteadof1，4qrsforCinsteadof2，and6forDinsteadof3；andcorrespondingly，themoney-rentforB，CandDwouldnowbe£；6，£；12，and£；18respectively。
Liketheyieldperacre，therentinmoneyperacrewouldbedoubled，and，consequently，alsothepriceofthelandwherebythismoney-rentiscapitalised。
Calculatedinthismanner，theamountofrentingrainandmoneyincreases，andthusthepriceofland，becausethestandardusedinitscomputation，i。e。，theacre，isanareaofconstantmagnitude。Ontheotherhand，calculatedasrateofrentoninvestedcapital，thereisnochangeintheproportionalamountofrent。Thetotalrentalof36istotheinvestedcapitalof20astherentalof18istotheinvestedcapitalof10。Thesameholdstruefortheratioofmoney-rentfromeachtypeofsoiltothecapitalinvestedinit；forinstance，inC，£；12rentisto£；5
capitalas£；6rentwasformerlyto£；21/2capital。Nonewdifferencesariseherebetweentheinvestedcapitals，butnewsurplus-profitsdo，merelybecausetheadditionalcapitalisinvestedinoneoftherent-bearingsoils，orinallofthem，withthesameproportionalyieldaspreviously。Ifthisdoubleinvestmenttookplace，forexample，onlyinC，thedifferentialrentbetweenC，BandD，calculatedwithrespecttocapital，wouldremainthesame:forwhentheamountofrentobtainedfromCisdoubled，soistheinvestedcapital。
Thisshowsthattheamountofrentinproduceandmoneyperacre，andthereforethepriceofland，mayrise，whilethepriceofproduction，therateofprofit，andthedifferencesremainunchangedandthereforetherateofsurplus-profitorofrent，calculatedwithrespecttocapital，remainsunchanged。
Thesamemaytakeplacewithdecreasingratesofsurplus-profit，andthereforeofrent，thatis，withdecreasingproductivityoftheadditionaloutlaysofcapitalthatstillyieldrent。Ifthesecondinvestmentsofcapitalof£；21/3hadnotdoubledtheoutput，butBhadyieldedonly31/2qrs，C——5qrs，andD——
7qrs，[IntheGerman1894editionthisreads:6qrs——Ed。]
thenthedifferentialrentforthesecond£；21/3ofcapitalinBwouldbeonly1/3qrinsteadof1，onC——1qrinsteadof2andonD——2qrsinsteadof3。Theproportionsbetweenrentandcapitalforthetwosuccessiveinvestmentswouldthenbeasfollows:
FirstInvestmentSecondInvestmentB:Rent£；3，Capital£；21/2Rent£；11/2，Capital£；21/2
C:”£；6，”£；21/2”£；3，”£；21/2
D:”£；9，”£；21/2”£；6，”£；21/2Inspiteofthisdecreasedrateofrelativeproductivityofcapital，andthusofthesurplus-profitcalculatedoncapital，therentingrainandmoneywouldhaveincreasedonBfrom1to11/3qrsfrom£；3to£；41/2，onC——from2to3qrsfrom£；6to£；9，andonD——from3to5qrsfrom£；9
to£；15。Inthiscase，thedifferencesfortheadditionalcapitals，comparedwiththecapitalinvestedinA，wouldhavedecreased，thepriceofproductionwouldhaveremainedthesame，buttherentperacre，andconsequentlythepriceoflandperacre，wouldhaverisen。ThecombinationsofdifferentialrentII，whichpresupposesdifferentialrentIasitsbasis，willnowbetakenup。
Capital，Vol。3，Chapter41KarlMarxCAPITALVol。III
THEPROCESSOF
CAPITALISTPRODUCTIONASAWHOLEPartVI
TRANSFORMATIONOFSURPLUS-PROFIT
INTOGROUNDRENTCHAPTER41
DifferentialRentII。
FirstCase:ConstantPriceofProductionTheassumptionhereimpliesthatthemarket-priceisregulatedasbeforebythecapitalinvestedintheworstsoilA。
I。Iftheadditionalcapitalinvestedinanyoneoftherent-bearingsoils——B，C，D——producesonlyasmuchasthesamecapitaluponsoilA，i。e。，ifityieldsonlytheaverageprofitattheregulatingpriceofproduction，butnosurplus-profit，thentheeffectupontherentisnil。Everythingremainsasbefore。ItisthesameasthoughanarbitrarynumberofacresofAquality，i。e。，oftheworstsoil，hasbeenaddedtothecultivatedarea。
II。Theadditionalcapitalsyieldadditionalproduceproportionaltotheirmagnitudeoneveryoneofthevarioussoils；inotherwords，thevolumeofproductiongrowsaccordingtothespecificfertilityofeachsoiltype——inproportiontothemagnitudeoftheadditionalcapital。
inChapterXXXIX，westartedwiththefollowingTableI:
TABLEI
TypeofsoilAcresCapital£；Profit£；PriceofProd。£；OutputQrsSellingprice£；Proceeds£；RentRateofSurplusprofitQrs£；
A121/21/23133000
B121/21/2323613120%
C121/21/2333926240%
D121/21/23431239360%*
Total410121030618Thisisnowtransformedinto:
TABLEII
TypeofsoilAcresCapital£；Profit£；PriceofProd。OutputQrsSellingprice£；Proceeds£；RentSurplusprofitQrs£；
A121/221/2=516236000
B121/221/2=51643226120%
C121/221/2=5166318412240%
D121/221/2=5168324618360%*
Total4201220601236Itisnotnecessaryinthiscasethattheinvestmentofcapitalbedoubledinallsoils，asinthetable。Thelawisthesamesolongasadditionalcapitalisinvestedinone，orseveral，oftherent-bearingsoils，nomatterinwhatproportion。Itisonlynecessarythatproductionshouldincreaseuponeverysoilinthesameratioasthecapital。Therentincreasesheremerelyinconsequenceofanincreasedinvestmentofcapitalinthesoil，andinproportiontothisincrease。Thisincreaseinproduceandrentinconsequenceof，andproportionatelyto，theincreasedoutlayofcapitalisjustthesameasregardsthequantityofproduceandrent，aswhenthecultivatedareaoftherent-bearingplotsoflandofthesamequalityhadbeenincreasedandtakenundercultivationwiththesameoutlayofcapitalasthatpreviouslyinvestedinthesametypesofsoils。InthecaseofTableII，forinstance，theresultwouldremainthesame，iftheadditionalcapitalof£；21/2peracrewereinvestedinanadditionalacreofB，CandD。
Furthermore，thisassumptiondoesnotimplyamoreproductiveinvestmentofcapital，butonlyanoutlayofmorecapitaluponthesameareawiththesamesuccessasbefore。
Allrelativeproportionsremainthesamehere。Ofcourse，ifwedonotconsidertheproportionaldifferences，butconsiderthepurelyarithmeticones，thenthedifferentialrentmaychangeuponthevarioussoils。Letus，assume，forinstance，thatadditionalcapitalhasbeeninvestedonlyinBandD。ThedifferencebetweenDandAisthen=7qrswhereaspreviouslyitwas=3，thedifferencebetweenBandA=3qrs，whereaspreviouslyitwas=1；thatbetweenCandB=？，whereaspreviouslyitwas=1，etcButthisarithmeticdifference，whichisdecisiveindifferentialrentIinsofarasitexpressesthedifferenceinproductivitywithequaloutlaysofcapital，isherequiteimmaterial，becauseitismerelyaconsequenceofdifferentadditionalinvestmentsofcapital，orofnoadditionalinvestment，whilethedifferenceforeachequalportionofcapitaluponthevariousplotsoflandremainsunchanged。
III。Theadditionalcapitalsyieldsurplus-produceandthusformsurplus-profit，butatadecreasingrate，notinproportiontotheirincrease。
TABLEIII
SoilAcresCapital£；Profit£；PriceofProd。£；OutputQrsSellingprice£；Proceeds£；RentRateofSurplusprofitQrs£；
A121/21/23133000
B121/221/2=516211/2=31/23101/211/241/290%
C121/221/2=51632=531539180%
D121/221/2=516431/2=71/23221/251/2161/2330%
171/231/22117511030Inthecaseofthisthirdassumption，itisagainimmaterialwhethertheadditionalsecondinvestmentsofcapitalareuniformlydistributedamongthevarioussoilsornot；whetherthedecreasingproductionofsurplus-profittakesplaceproportionatelyornot；whethertheadditionalinvestmentsofcapitalareallinthesamerent-bearingtypeofsoil，orwhethertheyaredistributedequallyorunequallyamongrent-bearingplotsoflandofvaryingquality。Allthesecircumstancesareimmaterialforthelawthatistobedeveloped。Theonlyassumptionisthatadditionalinvestmentsofcapitalyieldsurplus-profituponanyoneoftherent-bearingsoils，butindecreasingproportiontotheamountoftheincreaseincapital。
Thelimitsofthisdecrease，inthetablebeforeus，arebetween4quarters=£；12，theoutputfromthefirstoutlayofcapitalonthebestsoilD，and1quarter=£；3，theoutputfromthesameoutlayofcapitalintheworstsoilA。TheoutputfromthebestsoilincaseoftheinvestmentofcapitalIconstitutesthetoplimit，andtheoutputfromthesameoutlayofcapitalintheworstsoilA，whichyieldsneitherrentnorsurplus-profit，isthebottomlimitofoutput，whichsuccessiveinvestmentsofcapitalyielduponanyofthesoiltypesproducingsurplus-profitwithdecreasingproductivityofsuccessiveinvestmentsofcapital。JustasassumptionII
correspondstothecaseinwhichnewplotsofthesamequalityareaddedfromthebettersoilstothecultivatedarea，inwhichthequantityofanyoneofthecultivatedsoilsisincreased，soassumptionIIIcorrespondstothecaseinwhichadditionalplotsarecultivatedwhosevariousdegreesoffertilityaredistributedamongsoilsrangingfromDtoA，i。e。，fromthebesttotheworstsoils。IfthesuccessiveoutlaysofcapitalaremadeexclusivelyinsoilD，theymayincludetheexistingdifferencesbetweenDandA，thendifferencesbetweenDandC，andlikewisebetweenDandB。IftheyareallmadeinsoilC，thenonlydifferencesbetweenCandA，andCandB；ifexclusivelyinB，thenonlydifferencesbetweenBandA。
Butthisisthelaw:Therentincreasesabsolutelyuponallthesesoils，evenifnotinproportiontotheadditionalcapitalinvested。
Therateofsurplus-profit，consideringboththeadditionalcapitalandthetotalcapitalinvestedinthesoil，decreases；buttheabsolutemagnitudeofthesurplus-profitincreases；justasthedecreasingrateofprofitoncapitalingeneralis，inthemain，accompaniedbyanincreaseintheabsoluteamountofprofit。Thustheaveragesurplus-profitofacapitalinvestedinB=90%onthecapital，whereasitwas=120%forthefirstoutlayofcapital。Butthetotalsurplus-profitincreasesfrom1
qrto11/2qrs，orfrom£；3to£；41/2。
Thetotalrent-consideredbyitselfratherthaninrelationtothedoubledmagnitudeoftheadvancedcapital——hasrisenabsolutely。Thedifferencesinrentsfromvarioussoilsandtheirrelativeproportionsmayvaryhere；
butthisvariationindifferencesisaconsequence，notcause，oftheincreaseinrentsinrelationtooneanother。
IV。Thecaseinwhichadditionalinvestmentsofcapitalinthebettersoilsyieldmoreproducethantheoriginalonesrequiresnofurtheranalysis。
Itgoeswithoutsayingthatunderthisassumptiontherentperacrewillincrease，andproportionatelymorethantheadditionalcapital，nomatterinwhichkindofsoiltheoutlayhasbeenmade。Inthiscase，theadditionalinvestmentofcapitalisaccompaniedbyimprovements。Thisincludesthecasesinwhichanadditionaloutlayoflesscapitalproducesthesameoragreatereffectthananadditionaloutlayofmorecapitaldidformerly。
Thiscaseisnotquiteidenticalwiththeformerone，andthedistinctionisimportantinallinvestmentsofcapital。Forinstance，if400yieldsaprofitof40，and200employedinacertainformyieldsaprofitof40，thentheprofithasrisenfrom10%to20%，andtothatextentitisthesameasthough50employedinamoreeffectiveformyieldsaprofitof10insteadof5。Weassumeherethattheprofitisassociatedwithaproportionalincreaseinoutput。ButthedifferenceisthatImustdoublethecapitalintheonecase，whereasintheother，theeffectIproduceisdoubledwiththecapitalemployedhitherto。ItisbynomeansthesamewhetherIproduce:1thesameoutputasbeforewithhalfasmuchlivingandmaterialisedlabour，or2twicetheoutputasbeforewiththesamelabour，or3fourtimestheformeroutputwithtwicethelabour。Inthefirstcase，labour——inalivingormaterialisedform——isreleased，andmaybeemployedotherwise；thepowertodisposeofcapitalandlabourincreases。Thereleaseofcapitalandlabourisinitselfanaugmentationofwealth；ithasexactlythesameeffectasthoughthisadditionalcapitalhasbeenobtainedbyaccumulation，butitsavesthelabourofaccumulation。
Assumethatacapitalof100hasproducedanoutputoftenmetres。The100includesconstantcapital，livinglabourandprofit。Thusametrecosts10。Now，ifIcanproduce20metreswiththesamecapitalof100，thenametrecosts5。If，ontheotherhand，Icanproduce10metreswithacapitalof50，thenametrelikewisecosts5，andshouldtheformersupplyofcommoditiessufficeacapitalof50isreleased。IfIhavetoinvestacapitalof200inordertoproduce40metres，thenametrealsocosts5。Thedeterminationofvalue，andalsotheprice，doesnotpermitanydifferencetohediscernedhere；nomorethantheamountofoutputproportionaltotheoutlayofcapital。Butinthefirstcase，additionalcapitalissaved[IntheGerman1894editionthisreads:capitalisreleased——Ed。]
tobeusedperhapstodoubleproductionifnecessary；inthesecondcase，capitalisreleased，[Ibid。:additionalcapitalissaved——Ed。]
inthethirdcase，theincreasedoutputcanonlybeobtainedbyaugmentingtheinvestedcapital，althoughnotinthesameproportionaswhentheincreasedoutputwastohavebeensuppliedbytheoldproductivepower。ThisbelongsinPartI。
Fromtheviewpointofcapitalistproduction，theemploymentofconstantcapitalisalwayscheaperthanthatofvariablecapital，notasregardsincreasingthesurplus-value，butratherasregardsreducingthecost-price——andsavingofcostsevenintheelementcreatingsurplus-value，inlabour，performsthisserviceforthecapitalistandmakesprofitforhimsolongastheregulatingpriceofproductionremainsthesame。Thispresupposes，infact，thedevelopmentofcreditandanabundanceofloancapitalcorrespondingtothecapitalistmodeofproduction。Ontheonehand，Iemploy£；100
additionalconstantcapital，if£；100istheoutputoffivelabourersduringtheyear；ontheotherhand，£；100invariablecapital。Iftherateofsurplus-value=100%，thenthevaluecreatedbythefivelabourers=£；200；ontheotherhand，thevalueof£；100constantcapital=£；100andascapitalitisperhaps=£；105，iftheinterestrate=5%。Thesamesumsofmoneyexpressverydifferentvalues，fromtheviewpointoftheoutputtheyproduce，dependingonwhethertheyareadvancedtoproductionasmagnitudesofvalueofconstantorofvariablecapital。
Furthermore，asregardsthecostofthecommoditiesfromtheviewpointofthecapitalist，thereisalsothisdifference，thatofthe£；100
constantcapitalonlythewearandtearentersintothevalueofthecommodityinsofarasthismoneyisinvestedinfixedcapital，whereasthe£；100
investedinwagesmustbecompletelyreproducedinthecommodity。
Inthecaseofcolonists，andindependentsmallproducersingeneral，whohavenoaccesstocapitalatalloronlyathighinterestrates，thatpartoftheoutputwhichrepresentswagesistheirrevenue，whereasforthecapitalistitconstitutesanadvanceofcapital。Theformer，therefore，regardsthisexpenditureoflabourastheindispensableprerequisiteforthelabour-product，whichisthethingthatinterestshimaboveall。But，asregardshissurplus-labour，afterdeductingthenecessarylabour，itisevidentlyrealisedinthesurplus-product；andassoonashecansellthelatter，oruseitforhimself，helooksuponitassomethingthatcosthimnothing，becauseitcosthimnomaterialisedlabour。Itisonlytheexpenditureofthelatterwhichappearstohimasalienationofwealth。
Ofcourse，hetriestosellashighaspossible；butevenasalebelowvalueandbelowthecapitalistpriceofproductionstillappearstohimasprofit，unlessthisprofitisanticipatedbydebts，mortgages，etc。
Forthecapitalist，ontheotherhand，theinvestmentofbothvariableandconstantcapitalrepresentsanadvanceofcapital。Therelativelylargeradvanceofthelatterreducesthecost-price，andinfactthevalueofthecommodities，everythingelsebeingequal。Hence，althoughprofitarisesonlyfromsurplus-labour，consequentlyonlyfromtheemploymentofvariablecapital，itmaystillseemtotheindividualcapitalistthatlivinglabouristhemostexpensiveelementinhispriceofproductionwhichshouldbereducedtoaminimumbeforeallelse。Thisisbutacapitalisticallydistortedformofthefactthattherelativelygreateruseofcongealedlabour，ascomparedwithlivinglabour，signifiesanincreaseintheproductivityofsociallabourandagreatersocialwealth。Fromtheviewpointofcompetition，everythingappearsthusdistortedandturnedtopsy-turvy。
Assumingpricesofproductiontoremainunchanged，theadditionalinvestmentsofcapitalinthebettersoils，thatis，inallsoilsfromBupwardmaybemadewithunaltered，increasing，ordecreasingproductivity。ForsoilAthiswouldonlybepossibleundertheconditionsassumedbyus，ifproductivityremainsthesame——wherebythelandcontinuestoyieldnorent——andalsoifproductivityincreases；aportionofthecapitalinvestedinA
wouldthenyieldrent，whiletheremainderwouldnot。ButitwouldbeimpossibleifproductivityonAweretodecrease，forthenthepriceofproductionwouldnotremainunchanged，butwouldrise。Yetinallthesecases，i。e。，whetherthesurplus-productyieldedbytheadditionalinvestmentsisproportionaltothelatterorisgreaterorsmallerthanthisproportion——whether，therefore，therateofsurplus-profitonthecapitalremainsconstant，risesorfalls，whenthiscapitalincreases，thesurplus-productandthecorrespondingsurplus-profitperacreincreases，andhencealsothepotentialrentingrainandmoney。Thegrowthinthemerequantityofsurplus-profitorrent，calculatedperacre，thatis，anincreasingquantitycalculatedonthebasisofsomeconstantunit——inthepresentcaseonadefinitequantityoflandsuchasanacreorahectare——expressesitselfasanincreasingratio。Hencethemagnitudeoftherent，calculatedperacre，increasesundersuchcircumstancessimplyinconsequenceoftheincreaseinthecapitalinvestedintheland。Thistakesplace，tobesure，assumingthepricesofproductionremainthesame，and，ontheotherhand，regardlessofwhethertheproductivityoftheadditionalcapitalremainsunaltered，orwhetheritdecreasesorincreases。Thelattercircumstancesmodifytherangeinwhichthemagnitudeofrentperacreincreasesbutnottheexistenceofthisincreaseitself。ThisisaphenomenonpeculiartodifferentialrentII，anddistinguishingitfromdifferentialrentI。Iftheadditionalinvestmentsofcapitalweremadesuccessivelyinspace，sidebysideinnewadditionalSoilofcorrespondingquality，ratherthansuccessivelyintimeinthesamesoil，thequantityoftherentalwouldhaveincreased，and，aspreviouslyshown，sowouldtheaveragerentfromthetotalcultivatedarea，butnotthemagnitudeoftherentperacre。Giventhesameresultsofarasquantityandvalueoftotalproductionandsurplus-productareconcerned，theconcentrationofcapitaluponasmallerareaoflandincreasestheamountofrentperacre，whereasunderthesameconditions，itsdispersionoveralargerarea，allotherconditionsbeingequal，doesnotproducethiseffect。Butthemorethecapitalistmodeofproductiondevelops，themoredoestheconcentrationofcapitaluponthesameareaoflanddevelop，and，therefore，themoredoestherent，calculatedperacre，increase。
Consequently，giventwocountriesinwhichthepricesofproductionareidentical，thedifferencesinsoiltypeareidentical，andthesameamountofcapitalisinvested——butintheonecountrymoreintheformofsuccessiveoutlaysuponalimitedareaofland，whereasintheothermoreintheformofco-ordinatedoutlaysuponalargerarea——thentherentperacre，andtherebythepriceofland，wouldbehigherinthefirstcountryandlowerinthesecond，althoughthetotalrentwouldbethesameforbothcountries。
Thedifferenceinmagnitudeofrentcouldthusnotbeexplainedheretobearesultofadifferenceinthenaturalfertilityofthevarioussoils，noraresultofadifferenceinthequantityofemployedlabour，butsolelyaresultofdifferentwaysinwhichthecapitalisinvested。
Whenwerefertosurplus-producthere，thisshouldalwaysbeunderstoodtomeanthataliquotpartoftheoutputwhichrepresentssurplus-profit。
Ordinarily，wemeanbyexcessproductorsurplus-productthatportionoftheoutputwhichrepresentsthetotalsurplus-value，orinsomecasesthatportionwhichrepresentstheaverageprofit。Thespecificmeaningwhichthistermassumesinthecaseofrent-bearingcapitalgivesrisetomisunderstanding，aspreviouslypointedout。
Capital，Vol。3，Chapter42SKarlMarxCAPITALVol。III
THEPROCESSOF
CAPITALISTPRODUCTIONASAWHOLEPartVI
TRANSFORMATIONOFSURPLUS-PROFIT
INTOGROUNDRENTCHAPTER42
DifferentialRentII。
SecondCase:FallingPriceofProductionThepriceofproductionmayfallwhenadditionalinvestmentsofcapitaltakeplacewithanunaltered，falling，orrisingrateofproductivity。
I。Productivityoftheadditionalinvestmentofcapitalremainsthesame。
Inthiscase，theassumption，therefore，isthattheoutputincreasesproportionallytothecapitalinvestedinthevarioussoilsandinaccordancewiththeirrespectivequalities。Thismeansforconstantdifferencesinsoilsthatthesurplus-productincreasesinproportiontotheincreasedinvestmentofcapital。Thiscase，then，excludesanyadditionalinvestmentofcapitalinSoilAwhichmightaffectthedifferentialrent。Forthissoil，therateofsurplus-profit=0；thus，itremains=0sincewehaveassumedthattheproductivenessoftheadditionalcapital，andthereforetherateofsurplus-profit，remainthesame。
Butundertheseconditionstheregulatingpriceofproductioncanonlyfall，becauseitisthepriceofproductionofthenextbestsoil，ofB，oranybettersoilthanA，ratherthanthatofA，whichbecomestheregulator；
sothatthecapitaliswithdrawnfromA，orperhapsfromAandBifthepriceofproductionofCshouldbecometheregulatingone，andthusallsoilsinferiortoCwouldbeeliminatedfromthecompetitionamonggrain-producingsoils，Theprerequisiteforthisis，undertheassumedconditions，thattheadditionalyieldfromtheadditionalinvestmentsofcapitalsatisfythedemand，sothattheoutputfromtheinferiorsoilA，etc。，becomesuperfluousforthere-establishmentofafullsupply。
Thus，letustake，forinstance，TableII，butinsuchawaythat18
qrsinsteadof20satisfythedemand。SoilAwoulddropout；B*anditspriceofproductionof30shillingsperquarterwouldbecomeregulating。
Thedifferentialrentthenassumesthefollowingform:
TABLEIV
TypeofsoilAcresCapital£；Profit£；PriceofProd。OutputQrsSellingpriceperqr£；Proceeds£；RentRateofSurplusProfitInGrainQrsInMoney£；
B1516411/26000%
C1516611/292360%
D1516811/21246120%*
Total315318182769[*IntheGerman1894editionthisreads:D。？Ed。]
ComparedwithTableII，theground-rentwouldhencehavefallenfrom£；36to£；9，andingrainfrom12qrsto6qrs；totaloutputwouldhavefallenonlyby2qrs，from20to18。Therateofsurplus-profitcalculatedonthecapitalwouldhavefallentoone-third，i。e。，from180%to60%。[Ibid。:one-half，from180%to90%。朎d。]
Thus，thefallinthepriceofproductionisaccompaniedherebyadecreaseoftherentingrainandmoney。
ComparedwithTableI，thereismerelyadecreaseinmoney-rent；therentingrainisinbothcases6qrs；butintheonecaseit=£；18，andintheother£；9。ForSoilC，[Ibid。:forSoilCandD。？Ed。]
therentingrain，comparedwithTableI，hasremainedthesame。Infact，itisowingtotheadditionalproductionresultingfromtheuniformlyactingadditionalcapitalthattheyieldfromAhasbeenexcludedfromthemarket，andtherebysoilAhasbeeneliminatedasacompetingproducingagent，anditisowingtothisfactthatanewdifferentialrentIhasbeenformedinwhichthebettersoilBplaysthesameroleasdidformerlytheinferiorsoilA。
Consequently，ontheonehand，therentfromBhasdisappeared；ontheotherhand，nothinghasbeenalteredinthedifferencesbetweenB，CandDbytheinvestmentofadditionalcapital——inaccordancewithourassumption。
Forthisreason，thatpartoftheoutputwhichistransformedintorentisreduced。