貨幣擴張

貨幣擴張，也稱作貨幣創造(Money creation)，是中央銀行、商業銀行和非銀行（機構或個人）透過信貸關係共同作用，使得在銀行體系內流通貨幣量擴大的金融行為。
對貨幣擴張的控制是中央銀行的主要任務之一。
不是所有的流通貨幣都需要有貨幣現金、實物資產或政府資產作後盾。一國的貨幣是以國家的經濟潛力或政府的法定貨幣法令作後盾的。這種潛力也成為政府發行貨幣的理論上限。

**貨幣擴張乘數**
貨幣擴張乘數，也稱作存款創造乘數，描述商業銀行體系供給貨幣的機制，它衡量了商業銀行體系內增加貨幣供給的數量。為了控制這個體系創造的貨幣量，中央銀行給商業銀行設置嚴格的準備金比例，中央銀行只允許商業銀行的初級存款的一部分用於放貸，這也稱作現金準備比例。

**貨幣擴張乘數示例**
某儲戶在銀行A存入1000元初級存款(銀行負債部分的存款)，現金準備比例為12%，則120元必須被銀行保留(銀行資產部分的儲備)，880元可用於放貸(銀行資產部分的貸款)。如果銀行A將超額儲備880元全部放貸，接受貸款的人將之存到銀行B，銀行B需要將12%×880元作為初級存款880元的現金儲備，可放貸部分為774.40元。如果774.40元被存入C銀行，則92.93元須作為儲備，可以放貸681.47元，……，以此類推，直至不再有超額儲備(此處為了簡化，忽略了安全儲備)。
*TD：總存款的變化量
*ID：存款的初始變化
*crr：現金準備比例
例如，如果準備金比例為12%，存款的初始增長1000元將使總存款增加8333.33元(1000/.12=8333.33)。

**美元貨幣擴張示例**
#美國政府發行國庫券，即在特定日期支付特定金額的支付承諾。比如發行價值1,000,000美元的債券，投資者以貨幣進行投資購入債券，以獲得債券利息為報償。
#美聯儲印刷價值1,000,000美元的支票，作為應付款項給美國政府。該支票就是銷售債券的進款。
#

**模型構建**
B：實際資本 D：總資本 C：現金提取量 rd：活期存款準備金率 rt：定期存款準備金率 k：現金漏出率=C/D

**模型構建第一步**
B=rd×D+C
D=B/(rd+k）

**模型構建第二步**
引入超額準備金 Re e：超額準備金率
B=rd×D+C+Re
D=B/(rd+e+k）

**模型構建第三步**
引入定期存款T (t,定期存款佔活期存款比例）
B=rdXD+rt×T+C+Re
D=B/(rd+rt×t+e+k）

**延伸閱讀**
cite web|url= https://www.imf.org/external/pubs/ft/fandd/2012/09/pdf/basics.pdf|title= What Is Money?|last= Asmundson|first= Irena|author-link= |last2= Oner|first2= Ceyda|author-link2= |author-link3= |date= September 2012|website= Finance & Development|publisher= IMF|access-date= 8 March 2018|quote= |archive-date= 2021-05-03|archive-url= https://web.archive.org/web/20210503192351/https://www.imf.org/external/pubs/ft/fandd/2012/09/pdf/basics.pdf|dead-url= no
*dead-url=no 
*isbn= 978-0133061635
*ssrn = 2489665
*Cite web|url=https://www.kansascityfed.org/PUBLICAT/ECONREV/econrevarchive/1975/2q75cacy.pdf|title=Budget Deficits and the Money Supply|last=Cacy|first=J.A.|date=June 1975|publisher=Federal Reserve Bank of Kansas City|website=Monthly Review|language=en|access-date=8 March 2018|archive-date=2013-04-24|archive-url=https://web.archive.org/web/20130424132003/http://www.kansascityfed.org/PUBLICAT/ECONREV/econrevarchive/1975/2q75cacy.pdf|dead-url=no
*dead-url= no
*Cite web|url=http://www.bis.org/publ/work297.pdf|title=The bank lending channel revisited|last=Disyatat|first=Piti|date=February 2010|publisher=Bank of International Settlements|website=BIS Working Papers|language=en|access-date=8 March 2018|archive-date=2019-04-01|archive-url=https://web.archive.org/web/20190401153253/https://www.bis.org/publ/work297.pdf|dead-url=no
*Cite web|url=https://scholar.harvard.edu/files/mankiw/files/govdebt.pdf|title=The bank lending channel revisited|last=Elmendorf|first=Douglas W.|last2=Mankiw|first2=N. Gregory|author-link2=N. Gregory Mankiw|date=January 1998|publisher=Harvard University|website=Handbook of Macroeconomicss|language=en|access-date=8 March 2018|archive-date=2020-08-04|archive-url=https://web.archive.org/web/20200804071021/https://scholar.harvard.edu/files/mankiw/files/govdebt.pdf|dead-url=no
*dead-url=no
*cite web|url= http://www.businessinsider.com/japans-1-trillion-yen-of-debt-2013-8|title= Japan's Debt Has Officially Passed ¥1,000,000,000,000,000 — No Problem|last= Evans-Pritchard|first= Ambrose|author-link= Ambrose Evans-Pritchard|author-link2= |author-link3= |date= 10 August 2013|website= The Daily Telegraph|access-date= 8 March 2018|quote= |archive-date= 2019-08-05|archive-url= https://web.archive.org/web/20190805131001/https://www.businessinsider.com/japans-1-trillion-yen-of-debt-2013-8|dead-url= no- Federal Reserve historical statistics(11 June 2009)date=20090605101615 
*cite web |last=Garbade |first=Kenneth D. |url=https://www.newyorkfed.org/medialibrary/media/research/staff_reports/sr684.pdf |title=Direct Purchases of U.S. Treasury Securities by Federal Reserve Banks |date=August 2014 |website=FRBNY Staff Reports no. 684 |publisher=Federal Reserve Bank of New York |quote= |access-date=2020-03-20 |archive-date=2021-03-17 |archive-url=https://web.archive.org/web/20210317175702/https://www.newyorkfed.org/medialibrary/media/research/staff_reports/sr684.pdf |dead-url=no 
*author-link=
*cite web|url= https://files.stlouisfed.org/files/htdocs/publications/review/81/03/Deficits_Mar1981.pdf|title= Deficits and Inflation|last= Hein|first= Scott E.|author-link= |author-link2= |author-link3= |date= March 1981|website= |publisher= Federal Reserve Bank of St. Louis|access-date= 8 March 2018|quote= |archive-date= 2021-02-14|archive-url= https://web.archive.org/web/20210214005508/https://files.stlouisfed.org/files/htdocs/publications/review/81/03/Deficits_Mar1981.pdf|dead-url= no
*cite web|url= http://www.imf.org/external/pubs/ft/fandd/2014/03/pdf/basics.pdf|title= What Is Monetarism?|last= Jahan|first= Sarwat|author-link= |last2= Papageorgiou|first2= Chris|author-link2= |author-link3= |date= March 2014|website= Finance & Development|publisher= IMF|access-date= 8 March 2018|quote= |archive-date= 2020-06-15|archive-url= https://web.archive.org/web/20200615060259/https://www.imf.org/external/pubs/ft/fandd/2014/03/pdf/basics.pdf|dead-url= no
*cite journal |last=Kelton, née Bell|first=Stephanie|title=The Hierarchy of Money|date=1998  
publisher=The Jerome Levy Economics Institute|quote=|ssrn=96845
*dead-url=no 
*IMF (3 November 2017) " Monetary Policy and Central Banking date=20210430022849 "
*pages=81–107
*author-link= Greg Mankiw
*cite web|url= https://www.bankofengland.co.uk/-/media/boe/files/quarterly-bulletin/2014/money-creation-in-the-modern-economy.pdf|title= Money creation in the modern economy|last= McLeay|first= Michael|author-link= |last2= Radia|first2= Amar|author-link2= |last3= Thomas|first3= Ryland|author-link3= |date= 2014|website= Quarterly Bulletin|publisher= Bank of England|access-date= 8 March 2018|quote= |archive-date= 2021-05-16|archive-url= https://web.archive.org/web/20210516234607/https://www.bankofengland.co.uk/-/media/boe/files/quarterly-bulletin/2014/money-creation-in-the-modern-economy.pdf|dead-url= no
*cite web|url= https://files.stlouisfed.org/files/htdocs/publications/review/71/08/Central_Aug1971.pdf|title= Central Banks and The Money Supply|last= Meigs|first= A. James|author-link= |last2= Wolman|first2= William|author-link2= |author-link3= |date= 1971|website= Second Konstanz Seminar on Monetary Theory and Monetary Policy|publisher= Federal Reserve Bank of St. Louis|access-date= 8 March 2018|quote= |archive-date= 2020-10-18|archive-url= https://web.archive.org/web/20201018202716/https://files.stlouisfed.org/files/htdocs/publications/review/71/08/Central_Aug1971.pdf|dead-url= no
*cite book|last=Mishkin|first=Frederic S.|authorlink=Frederic Mishkin|title=The economics of money, banking and financial markets|url=https://spu.fem.uniag.sk/Marian.Toth/finance/20142015/MBFM.pdf|location=Canada|publisher=Addison-Wesley|year=2011|orig-year=2002|edition=4th|isbn=978-0-321-58471-7|pages=|access-date=2020-03-20|archive-url=https://web.archive.org/web/20180310074333/https://spu.fem.uniag.sk/Marian.Toth/finance/20142015/MBFM.pdf|archive-date=2018-03-10|dead-url=yes
*isbn= 978-1-85898-507-7
*dead-url= no
*cite web|url= https://www.imf.org/external/pubs/ft/tnm/2012/tnm1202.pdf|title= Government Cash Management: Relationship between the Treasury and the Central Bank|last= Pessoa|first= Mario|author-link= |last2= Williams|first2= Mike|author-link2= |author-link3= |date= November 2012|website= Fiscal Affairs Dept|publisher= International Monetary Fund|access-date= 8 March 2018|quote= |archive-date= 2020-10-19|archive-url= https://web.archive.org/web/20201019145703/https://www.imf.org/external/pubs/ft/tnm/2012/tnm1202.pdf|dead-url= no
*dead-url= no
*dead-url=no 
*url-access= registration
*author-link=Joseph A. Schumpeter
*dead-url=no 
*Standard & Poor's (13 August 2013) " Repeat after me: Banks cannot and do not lend out reserves date=20181009145902 ", Ratings Direct
*dead-url=no
*ssrn = 2489665
*doi=10.1016/j.irfa.2015.08.014
*Cite journal|title=Money and Inflation|last=Wray|first=L. Randall|author-link=L. Randall Wray|date=1 September 2000|publisher=University of Missouri-Kansas City|language=en|ssrn = 1010331