Marginal nqi hluav taws xob - ib tug purchase hais tias ib tug neeg tau txais thaum siv ib tug ntxiv chav tsev ntawm nyiaj poob haujlwm. Yog hais tias ntshiab kev sib tw los ntawm qhov ntsuas no, koj yuav txiav txim seb tus nqi lag luam ntawm cov khoom.
Tom qab
Peb hais tau tias txoj kev cai marginal nqi hluav taws xob qhia txog cov kev nce rau hauv tag nrho cov kev pab cuam nyob rau hauv cov nqe lus ntawm ntxiv kev pab rau lwm ntawm tau. Qhov no tej ntsiab cai muaj teev tawm yuav luag ib txhij los ntawm peb cov tseem ceeb zaum-economists: Leon Walras, Karlom Mengerom, thiab Stanley Jevons. Xeem teev tseg nws lub tswv yim rau cov kawm nyob rau hauv lub qhuab qhia, uas yog luam tawm nyob rau hauv 1866 los ntawm Carl Menger tham txog qhov no qhov teeb meem nyob rau hauv lub "Principles of Political Economy" nyob rau hauv 1871. Leon Walras hais rau qhov no qhov teeb meem nyob rau hauv 1874. Nyob rau tib lub sij hawm, tag nrho peb tau ua hauj lwm rau cov teeb meem ntawm nws tus kheej. Nco ntsoov tias lub marginal nqi hluav taws xob - ib lub sij hawm qhia nyob rau hauv kev lag luam Friedrich von Wieser. Xav txog cov tswv yim yooj ntsiab cai ntawm no phenomenon. Nyob rau hauv raws li cov nqi ntawm ib tug tej yam zoo ntawm cov kev pab yog txiav txim nyob rau hauv raws li cov nqi hluav taws xob ntawm marginal Piv txwv uas satisfies cov tsawg kawg ceev yuav tsum tau.
zaj dabneeg
"Marginal nqi hluav taws xob" - ib tug tswvyim uas thawj mus niaj hnub economists thaum lawv ua hauj lwm rau lub hom phiaj ntawm tus nqi. Xav txog dab tsi zaum hnub no yog investing nyob rau hauv no lub sij hawm. Lawv to taub nws raws li tus tsawg kawg yog ib qho tseem ceeb hauv daim ntawv ntawm cov kev pab cuam coj los ntawm ib tug meej boon nyob rau hauv lub rooj sib tham ib tug neeg xav tau kev pab. Piv txwv, piv txwv li, khob cij uas muaj peev xwm mus ua hauj lwm raws li distillation, tsiaj nyeg pub, thiab cov zaub mov qoob loo. Nws yuav suav hais tias tus thawj ntawm lub kawg tseem ceeb luag hauj lwm. Lub peev xwm ntawm lub khob cij los siav no yuav tsum tau yuav suav hais tias nws marginal nqi hluav taws xob. Nyias nws yog tsim nyog them sai sai mus rau lwm tseem ceeb feature ntawm no phenomenon. Txawm nyob rau hauv relation mus rau cov kev xav ntawm ib tug kev pab ntawm cov muaj peev xwm txaus siab rau ntau yam marginal nqi hluav taws xob. Raws li ib qho piv txwv, xav txog qhov tseem ceeb ntawm lub khob cij rau cov tshaib plab thiab lub satiated txiv neej. Peb txaus siab nyob rau hauv index decreases nrog tshaj cov kev pab thiab nce nyob rau hauv nws tsis muaj.
ntog
Tam sim no peb sib tham txog nyob rau hauv ntau dua kom meej raws li txoj cai ntawm ploj zuj zus marginal nqi hluav taws xob. Nws hais tias vim txoj kev loj hlob ntawm kev noj zoo tag nrho nqi hluav taws xob nce, tab sis tus nqi ntawm txoj kev no yog slowed down. Tam sim no siv ib tug saib txoj kev cai ploj zuj zus marginal nqi hluav taws xob los ntawm ib tug zauv taw tes ntawm view. Peb nrhiav tau hais tias thawj thawj derivative ntawm ib tug tag nrho nqi hluav taws xob muaj nuj nqi yog zoo thiab yog nyob rau hauv lub noj ntawm cov khoom. Txawm li cas los, nws decreases. Wherein lub thib ob derivative yog tsis zoo. Ploj zuj zus marginal nqi hluav taws xob tshwm li ib tug zuj zus muaj nuj nqi uas yog convex upward. Peb txaus siab nyob rau hauv index nrog ib qho kev nce rau hauv kev noj decreases. Nyob rau hauv tej yam kev mob ntawm lub siab tshaj plaws kev nqi hluav taws xob nws vanishes. Tom qab hais tias, lub marginal nqi hluav taws xob yuav tsis zoo. Zuag qhia tag nrho, nyob rau hauv lem, nce mus txog ib tug tshaj plaws thiab pib kom txo tau. Piv txwv li, yog hais tias peb tham txog cov neeg tshaib plab, lub marginal nqi hluav taws xob ntawm tus thawj heev tais ntawm kua zaub rau nws yog ntau ntau piv rau lub thib ob. Qhov no kuj muaj tseeb rau lwm hom ntawm cov khoom.
Limited applicability ntawm txoj cai
Koj muaj peev xwm tsuas piv khoom muaj homogeneous units, uas yog noj los ntawm ib tug neeg. Piv txwv li, txiv tsawb thiab apples yuav tsis tau saib. Txawm me me sib txawv tej zaum yuav muaj kev cuam tshuam zaum kawg tshwm sim. Piv txwv li, yuav tsis pom nrog liab thiab ntsuab apples. Tag nrho cov chav ntawm lub khoom yuav tsum muaj lub zoo tib yam thiab qhov hnyav. Piv txwv li, apples yog qaub thiab qab zib. Qhov thib ob yog ib qho ua muaj peev xwm muab ntau dua neeg siab. Peb xav txog lub buyer nrog tib tastes. Lawv yuav tsis tsum hloov nyob rau hauv cov nyiaj tau, nyiam, kev lis kev cai thiab cwj pwm tsis zoo ntawm cov kev pab. Cov kev hloov nyob rau hauv ib yam ntawm cov yam tseem ceeb los cuam tshuam rau cov qab hau ntawm cov khoom, thiab piav txog tus kev cai lij choj yuav tsis tau mus thov. Tsis tas li ntawd rau mis yuav tsum tau tas mus li noj. Yog hais tias tus mob no yog tsis coj mus rau hauv tus account, lub marginal nqi hluav taws xob yuav tsis kam nqes. Thaum twg, tom qab noj nqos tau cov thawj chav tsev ntawm cov khoom yog pom mas, nws yog yuav hais tias qhov yuav tsum tau rau nws rov pib dua. Yog li, los ntawm cov nram qab no zoo units yuav muaj ib tug zoo xws li cov siab.
nthuav lus tseeb
Marginal nqi hluav taws xob - nws cov nuj nqis uas ua pov thawj tias txos nqi txhawb tau txais kev pab rau nce tus naj npawb ntawm kev yuav khoom ntawm ib tug tej khoom. Txawm li cas los, piav txog tus kev cai lij choj tsis yog ib txwm tam sim no. Nyob rau hauv kev, tej zaum nws yuav tsis ua hauj lwm nyob rau hauv cov ntaub ntawv ntawm ib tug me me npaum li cas ntawm cov khoom. Cov ntaub ntawv no muaj peev xwm yuav taw qhia los ntawm ib qho piv txwv ntawm ib tug kho mob. Piv txwv li, yog tias ib tug neeg haus ib ntsiav tshuaj, nws yuav tsis siab kho tau zoo. Yog hais tias ob tug ntawm lawv - zoo yog tau nyob rau hauv tag nrho. Tab sis qhov ntxiv siv cov ntsiav tshuaj no tsuas yog muaj peev xwm ua phem rau lub cev. Raws li ib tug tshwm sim, marginal nqi hluav taws xob yuav tig mus rau hauv ib tug tsis zoo.