Ka'ida ta biyu mafi muhimmanci ta jari-hujja (capitalism) ita ce ka'idar da ke bayyana darajar kaya. Darajar kaya ita ce matakin muhimmancinta, dangane da wani takamaiman mutum ko dangane da wani abu. Idan ana amfani da darajar dangane da mutum, ana kiranta "darajar amfani," ko kuma kawai "amfani." Idan kuma ana auna ta da wani abu, ana kiranta "darajar musaya" ko kuma kawai "daraja." A karkashin jari-hujja, ana tantance darajar amfanin abu ta hanyar amfanin gefe (marginal benefit). Amfanin gefen wani yanki shi ne wannan amfanin da ke biyan bukata mafi rauni. Wannan ana kiransa ka'idar "raguwar amfanin gefe" (diminishing marginal utility). A cewar wannan ka'ida, ba a tantance amfani daga mahangar mai samarwa da kudin samarwa kawai; hakan zai duba samarwa ne kadai ba bukata ba. Haka kuma ba a tantance shi daga mahangar mabukaci kadai (amfani, sha'awa, da samuwa ko karancin abu dangane da wasu); hakan zai kai ga duba bukata ba tare da samarwa ba. Ya kamata a lura da tantance darajar amfani daga mahangar samarwa da bukata tare.

The second major principle of capitalism is the principle which defines the value of the product. The value of the product is the degree of its importance, relative to a particular person or relative to another thing. When the value is used relative to a person, it is called “the value of the benefit,” or simply the “benefit.” When measured against another thing, it is called the “value of exchange” or simply the “value.” Under capitalism, the value of the benefit of a thing is evaluated by its marginal benefit. The marginal benefit of a unit is that benefit which satisfies the weakest need. This is known as “the diminishing marginal utility” theory38. According to this theory, the benefit is not evaluated from the viewpoint of the producer and the costs of production only; this would only consider supply but not demand. Nor is it evaluated from the viewpoint of the consumer alone (benefit, desirability, and relative availability or shortage); this would imply the consideration of demand without supply. The benefit value should be observed and evaluated from the viewpoint of both supply and demand.

Yawan amfanin abu ya kamata a auna shi a mafi ƙarancin matakin gamsuwa. Misali, darajar gurasa ya kamata a auna ta a lokacin da yunwa ta fi ƙanƙanta, ba a lokacin da kowa yana jin yunwa ko lokacin da wanda yake buƙatar gurasar ya fi ƙarfin yunwa. A wata ma'ana, ana auna darajar amfanin gurasar a lokacin da gurasa ta yalwata a kasuwa, ba a lokacin da gurasa ta yi ƙaranci ba. Dokar raguwar amfanin gefe ba koyaushe take aiki ba, kamar yadda za mu gani daga baya; wannan na iya zama ɗaya daga cikin tushen lahani da kurakurai maɓoyi a cikin tushen tsarin jari-hujja.

Marginal utility states that the benefit of a thing should be assessed at the least or minimum point of satisfaction. For example, the value of a loaf of bread should be assessed at the least point of hunger and should not be assessed when everybody is hungry or when the one who needs the bread is too hungry. In other words, the benefit value of the bread is measured at a time when bread is abundant in the market, not at a time when there is a shortage of bread. The law of diminishing marginal utility does not always hold as we shall see later; this could very well be one of the sources of defects and dormant faults in the foundation of capitalism.

Ƙimar musaya siffa ce da ke sa wani abu ya dace a musanya shi da wasu kayayyaki. Ƙarfin musayar wani abu ana auna shi ne dangane da wani abu. Misali, ƙimar musayar alkama dangane da masara ana kimanta ta ne da adadin raka'o'in masara da ya kamata a bayar don samun raka'a ɗaya ta alkama.

The exchange value is an attribute which makes a thing suitable for exchange with other products. The strength of exchange of a thing is measured relative to another thing. For example, the value of exchange of wheat relative to corn is estimated by the number of units of corn which should be conceded to obtain one unit of wheat.

Musayar kayayyaki ko ayyuka yana faruwa tsakanin abubuwa biyu da suke daidai ko kusa da juna a darajarsu. Nazarin darajar musaya yana da muhimmanci ga masana tattalin arziki domin shi ne tushen musayar kayayyaki. Yana kuma zama amfani wanda za a iya aunawa; haka kuma yana aiki a matsayin ma'auni da ake auna kayayyaki da ayyuka da shi, kuma ta hanyarsa ake iya auna yawan amfanin ayyuka.

Exchange occurs between two commodities or services which are similar or close in their values. The study of the exchange value is necessary for economists because it is the basis for the exchange of products. It is a utility which can be measured; it also serves as a scale with which commodities and services are measured and by which the productivity of actions can be measured.

Samarwa an bayyana shi a matsayin aikin da ake zuba don samar da amfani ko ƙara amfani a cikin wani abu. Domin a gane ko wani aiki yana da amfani wajen samarwa ko a tantance wane aiki ne yake da ƙarfin samarwa mafi girma, dole ne a sami ma'auni mai inganci da za a iya auna yawan samarwa da shi. Wannan ma'auni shi ne darajar al'umma ta kayayyaki da ayyuka daban-daban. A wasu kalmomi, shi ne kimanta gamayya na aikin da aka yi da kuma hidimar da aka bayar. Irin wannan kimantawa wajibi ne saboda a zamanin yau, samarwa don musayar kaya ya mamaye, kuma kusan ya maye gurbin samarwa don amfanin kai. A tattalin arzikin yau, kusan kowane mutum yana musayar abin da ya samar da abin da wasu suka samar. Hanya madaidaiciya ta musayar kayayyaki da ayyuka ita ce ta biyan diyya. Domin kimanta adadin diyyar kayan ko hidima, wajibi ne a kimanta darajar musayar. Saboda haka, sanin da ma'anar "daraja" muhimmin abu ne a samarwa da amfani; yana da muhimmanci ga dukkan nazarin da ke kai ga biyan buƙatu.

Production is defined as the work invested for creating benefit or increasing benefit in a thing. In order to identify whether a work is productive or not or to determine which work has greater productivity, there must be an accurate scale by which productivity can be measured. This scale is the societal value of the various products and services. In other words, it is the collective evaluation of the work spent and the service provided. Such an evaluation is necessary because in the modern time, production for the purpose of exchange has dominated and almost replaced production for consumption. In today’s economy, virtually every person exchanges his/her production with other people’s production. The proper way of exchanging products and services is through compensation. In order to estimate the amount of compensation for a product or service, the value of exchange needs to be estimated. Hence, the knowledge and definition of the “value” is an essential factor in production and consumption; it is essential for all the studies leading to the satisfaction of the needs.

A cikin tarihin zamani, wannan darajar musaya ta mamaye ta hanyar nau'in musaya guda ɗaya, wato musayar kaya ko hidima da kuɗi. Darajar musayar kaya ko hidima da kuɗi ana kiranta "farashi." Farashi, saboda haka, shi ne adadin musayar kaya ko hidima dangane da kuɗi. Bambancin da ke tsakanin darajar musaya da farashi shi ne cewa darajar musaya ita ce ma'aunin musayar abu ɗaya dangane da wani abu (kowane) daban, yayin da farashi shi ne ma'aunin musayar abu ɗaya dangane da kuɗi. Ana iya fahimtar cewa farashin dukkan kaya suna tashi ko faɗuwa a lokaci guda. Sai dai kuwa, ba zai yiwu ba darajar musayar dukkan kayayyaki dangane da juna su tashi ko faɗuwa a lokaci guda. Haka nan yana yiwuwa farashin kayayyaki su canza ba tare da hakan ya haifar da canji a darajar musayarsu ko darajar amfanin su ba. Farashin kaya guda ɗaya kawai ɗaya ne daga cikin darajojinsa; shi ne darajar kaya dangane da kuɗi. Ta haka ne, a zahiri, farashi ya zama ma'auni da ake amfani da shi wajen tantance ko wani abu yana da amfani ko babu, da kuma ayyana matakin amfanin wannan abu. Kaya ko hidima ana ɗaukarta mai amfani ko mai fa'ida idan al'umma sun sanya babban farashi a kanta. Matakin amfanin wannan kaya ko hidima ana aunawa ne ta farashin da yawancin masu sayayya suka amince su biya don mallakarsa ko amfani da shi. Kayayyaki da hidimomin da ake auna su da farashi na iya zama kowane kaya ko hidima: kayan noma ko masana'anta; hidimar ɗan kasuwa ko kamfanin sufuri, likita ko injiniya.

In modern history, this value of exchange has been dominated by one type of exchange, the exchange of a product or service for money. The exchange value of a commodity or a service for money is called the “price.” The price, therefore, is the amount of exchange of a commodity or a service relative to money. The difference between the value of exchange and the price is that the value of exchange is the exchange ratio of one thing related to (any) other thing, while the price is the exchange ratio of one thing related to money. It is perceivable that the prices of all goods rise or fall at the same time. It is impossible, however, for the exchange values of all commodities relative to each other to rise or fall at the same time. It is also possible for the prices of commodities to change without resulting in a change in their value of exchange or value of benefit. The price of a commodity is only one of its values; it is the value of a commodity relative to money. Naturally, the price has become the de facto scale for deciding whether a thing is beneficial or not and for defining the degree of benefit of that thing. The commodity or the service is considered productive or beneficial if the society puts a high price for this commodity or service. The degree of benefit of this commodity or service is measured by the price which the majority of the consumers agree to pay for possessing or utilizing it. Products and services evaluated by a price can be any commodity or service: agricultural or industrial product; the service is that of a trader or transportation company, doctor or engineer.

Darajar kaya a karkashin tsarin jari-hujja dai dangantaka ce (ta zahiri) ba cikakkiya ba. Misali, darajar gurasa guda ita ce amfanin karshe da take bayarwa idan aka ɗauka cewa gurasa tana da yawa a kasuwa; wannan kuma yana dogara ne akan ra'ayin raguwar amfanin karshe. Idan aka ba wanda yake jin yunwa gurasa guda kuma gurasa ba ta da yawa, to darajarta tana da tsada sosai. Darajar takan ragu har sai ta tsaya cik idan mutanen da ke neman gurasar ba su ƙara jin yunwa ba kuma akwai isasshiyar gurasa ga wadanda suke son saye. Don haka ya kamata a kiyasta darajar (wato amfanin kayan) a lokacin da bukatar kayan ta yi ƙasa kuma samar da kayan ya yi yawa.

he value of a commodity under capitalism is a relative (virtual) one and not absolute. The value of a loaf of bread, for example, is its marginal benefit assuming that the bread is abundant in the market; this is based on the diminishing marginal utility concept. When the loaf of bread is offered to one who is hungry and the bread is scarce, the value of the bread is too high. The value diminishes until it settles down when the people demanding the bread are no longer hungry and there is enough bread for those who want to acquire it. So the value (which is the benefit of the product) needs to be estimated at the time when the demand for the product is the lowest and the supply of the product is plentiful.

Samfurin yana da wata ƙima, wadda ita ce ƙimar musaya. Ƙimar musaya ita ce adadin kayayyaki da ƙoƙarin aiki da za a iya musanya su da shi a madadin gurasar. Ƙimar ta zama farashi idan abin da aka samu a madadin gurasar kuɗi ne. Waɗannan ƙima biyu, a ƙarƙashin tsarin jari-hujja, sun bambanta da juna, kuma suna da sunaye daban-daban guda biyu: amfani, da ƙimar musaya ko kuɗi.

The product also has another value, which is the exchange value. The exchange value is the quantity of commodities and efforts that could be exchanged in return for the loaf of the bread. The value becomes a price if what is obtained for the loaf of the bread is money. These two values, under capitalism, are separate, and have two distinct names, benefit and the value of exchange or money.

Ta'rifin darajar nan ba daidai ba ne. Lura cewa a cikin dukkan ra'ayoyin biyu na daraja (amfani da farashi), mai kimantawa yana auna daraja dangane da mai amfani. Wannan ra'ayi ba ya ba da wani ma'auni na amfanin kayan da kansa. A misalin buredi, ta'rifin darajar ba ya nufin amfanin da ke cikin buredi a ma'anar cewa buredi yana da wata siffa ta kawar da yunwa. A gaskiya, darajar buredi ita ce adadin amfanin da ke cikinsa. Idan aka auna wannan adadi, ya kamata a yi la'akari da abin ƙarancin, amma bai kamata ya zama abin da zai bayyana darajar ba. Wannan ra'ayi na daraja (adadin amfanin da ke cikin kayan) yana aiki ko an samu kayan ta hanyar farauta, ƙera, noma, sayarwa, ko saye. Amfanin yana nan iri ɗaya ko yana da alaƙa da mutum ko da wani abu, ko kayan yana da yawa ko ƙaranci. Lallai, daraja suna ne na wani abu na musamman wanda yake da wani gaskiya ta musamman; ba suna ba ne na abu mai alaƙa, wanda ke canzawa a kan lokaci da daga wani yanayi zuwa wani. A wasu kalmomi, darajar ya kamata ta zama ma'auni na amfani mai manufa, ba ma'auni mai alaƙa ba.