John Burr Williams

**John Burr Williams** (27 ga Nuwamba, 1900 - 15 ga Satumba, 1989) masanin tattalin arziki ne na Amurka, wanda aka amince da shi a matsayin mutum mai muhimmanci a fannin nazarin asali, da kuma nazarin farashin hannayen jari a matsayin wanda ke nuna " ƙimarsu ta asali ". 

Ya fi shahara da rubutunsa na 1938 *mai suna The Theory of Investment Value*, wanda ya dogara ne akan takardar digirinsa na PhD, inda ya bayyana ka'idar kimantawa bisa ga rangwamen kuɗaɗen shiga (DCF), musamman ma, kimantawa bisa ga rabon riba .

## Tarihin Rayuwa
Williams ya yi karatun lissafi da sinadarai a Jami'ar Harvard, kuma ya yi rajista a Makarantar Kasuwanci ta Harvard a shekarar 1923. Bayan kammala karatunsa, ya yi aiki a matsayin mai sharhi kan tsaro, inda ya fahimci cewa "yadda ake kimanta darajar da ta dace hakika abin mamaki ne... Domin zama ƙwararren mai sharhi kan saka hannun jari, mutum yana buƙatar zama ƙwararren masanin tattalin arziki ."  A shekarar 1932 ya yi rajista a Harvard don digirin digirgir a fannin tattalin arziki, da fatan sanin abin da ya haifar da faduwar Wall Street a shekarar 1929 da kuma koma bayan tattalin arziki da ya biyo baya a shekarun 1930.  Don takardar neman digirinsa, Joseph Schumpeter ya ba da shawarar tambayar ƙimar hannun jari ta gama gari, wanda gogewar Williams da tarihinsa za su yi masa amfani. Ya sami digirin digirgir a shekarar 1940.

Williams ya aika da *Ka'idar Darajar Zuba Jari* don bugawa kafin ya sami amincewar malamai don digirin digirgir. Aikin ya tattauna ka'idar Williams gabaɗaya, da kuma samar da samfuran lissafi sama da 20; kuma ya ƙunshi sashe na biyu da aka keɓe don nazarin shari'o'i. Mawallafa daban-daban sun ƙi aikin tunda yana ɗauke da alamomin algebra, kuma Harvard University Press ta buga *Ka'idar Darajar Zuba Jari* a 1938,  sai bayan Williams ya amince ya biya wani ɓangare na kuɗin bugawa. Aikin ya yi tasiri tun lokacin da aka buga shi; Mark Rubinstein ya bayyana shi a matsayin "wani abu da ba a yaba masa sosai ba". 

Daga shekarar 1927 har zuwa rasuwarsa, Williams ya yi aiki a fannin kula da harkokin saka hannun jari na masu zaman kansu da kuma nazarin tsaro . Ya koyar da nazarin tattalin arziki da zuba jari a matsayin farfesa mai ziyara a Jami'ar Wisconsin–Madison ; ya kuma rubuta labarai da yawa don mujallun tattalin arziki.  A yau, kamfaninsa na gudanar da saka hannun jari mai zaman kansa, Burr and Company, LLC .

## Ka'ida
Williams yana cikin waɗanda suka fara ƙalubalantar ra'ayin " gidan caca " da masana tattalin arziki ke riƙe da shi game da kasuwannin kuɗi da farashin kadarori - inda farashin ke ƙayyade galibi ta hanyar tsammani da tsammanin riba mai kyau  (duba gasar kyau ta Keynesian ). Ya yi jayayya cewa kasuwannin kuɗi, maimakon haka, " kasuwanci ne ", a zahiri, kuma farashin ya kamata ya nuna ƙimar kadarori.  ( *Ka'idar Darajar Zuba Jari* ta fara da: "Abubuwa daban-daban waɗanda ba za a ruɗe su ba, kamar yadda kowane mai zuba jari mai tunani ya sani, suna da ƙima da farashin kasuwa..."). Ta haka, ya canza mayar da hankali daga jerin lokaci na kasuwa zuwa abubuwan da ke ƙarƙashin ƙimar kadarori. Maimakon yin hasashen farashin hannun jari kai tsaye, Williams ya jaddada samun riba da rabon riba na kamfanoni na gaba. 

Ta hanyar haɓaka wannan ra'ayin, Williams ya ba da shawarar cewa ya kamata a ƙididdige ƙimar kadara ta amfani da "ƙimar ta hanyar ƙa'idar ƙimar yanzu". Don haka, ga hannun jari na gama gari, ƙimar da ke cikin ciki, ta dogon lokaci ita ce ƙimar yanzu ta kwararar kuɗin sa na gaba - a cikin nau'in rarraba hannun jari da farashin siyarwa.  A ƙarƙashin sharuɗɗan *tabbas*,  ƙimar hannun jari, saboda haka, ita ce ƙimar da aka rage wa duk rabon da za a samu a nan gaba; duba samfurin Gordon .

Duk da cewa Williams bai samo asali daga ra'ayin ƙimar yanzu ba,  ya tabbatar da ra'ayin ƙimar ƙimar kwararar kuɗi mai rahusa kuma galibi ana ɗaukarsa a matsayin wanda ya ƙirƙiro tushen tsarin rangwamen rabon riba (DDM).   Ta hanyar tsarinsa na ƙira da hasashen kwararar kuɗi - wanda ya kira "kasafin kuɗi na algebraic" - Williams shi ma ya kasance majagaba na ƙirar bayanan kuɗi na  .  A nan, Williams ( *Ka'ida*, babi na 7) ya ba da tattaunawa ta farko game da zagayowar rayuwar masana'antu.

A yau, "ƙimar da aka yi amfani da ita bisa ga ƙa'idar darajar yanzu", wanda aka yi amfani da shi tare da ƙimar rangwame mai dacewa da kadarori - yawanci ana samun ta ta amfani da tsarin farashin kadarorin jari ( Harry Markowitz da William F. Sharpe ), ko ka'idar farashin sassautawa ( Stephen Ross ) - wataƙila ita ce hanyar ƙimar hannun jari da aka fi amfani da ita tsakanin masu zuba jari na cibiyoyi ;  duba Jerin batutuwan kimantawa . (Nicholas Molodovsky, tsohon editan mujallar *Financial Analysts Journal*, shine na farko da ya maye gurbin "rabin riba" a cikin dabarar Williams don: ribar da ta ninka kashi na ribar da aka biya a cikin rabon riba.  )

Williams ya kuma yi hasashen ka'idar Modigliani-Miller . A lokacin da yake gabatar da "Dokar Kare Darajar Zuba Jari" ( Ka'idar, shafi na 72), ya yi jayayya cewa tunda darajar kasuwanci ita ce "darajar yanzu" na duk rabon da za a samu a nan gaba - ko riba ko rabon riba - "ba ta dogara da yadda jarin kamfanin yake ba". Modigliani da Miller sun nuna cewa Williams, duk da haka, bai tabbatar da wannan doka ba, domin bai bayyana yadda damar sasantawa za ta taso ba idan Dokarsa ta gaza.

## Littattafai

*  
* *International trade under flexible exchange rates*. 1954
* *Interest, Growth and Inflation* 1964; 1998 reprint, Fraser Publishing. ISBN&nbsp;

## Duba kuma

* Benjamin Graham
* Warren Buffett
* Irving Fisher
* Philip Fisher
* Zuba jari mai daraja
* Corporate finance § Zuba jari da kimanta aikin
* Financial economics § Ka'idar kuɗi ta kamfanoni
* Kimantawa ta amfani da rangwamen kuɗi kwararar kuɗi

## Manazarta