為了防止銀行恐慌的發生，我們首先需要知道它產生的原因：股市的崩潰、房地產泡沫的破裂（主要由銀行信貸的快速膨脹引起）導致物價下跌、銀行資產減值。存款人因資不抵債從銀行取出存款，銀行繼而陷入了流動性危機。
銀行的業務性質使其很容易受到流動性危機的影響。銀行的主要盈利來源是短期存款和長期貸款，這通常被稱作期限轉換（或到期日的不匹配）。銀行通過短期存款和長期貸款的利率差可以獲得不菲收益。
如果沒有期限轉換，那麼金融危機也將變得十分罕見。銀行只需要借助短期存款來實現短期貸款義務，而不需要美聯儲提供額外的流動性。存在的唯一危機可能性就是借貸人的償付能力。
銀行在以下兩個重要方面受到聯邦政府的保護：
1、 聯邦政府的存款保險保證了銀行對存款人的償付能力。
2、 銀行可以從美聯儲的貼現窗口獲得流動性。
納稅人充當了銀行系統的緩沖器作用：納稅人為銀行的壞賬買單，為銀行提供了額外的流動性。銀行體系的崩潰必然會拖垮整個經濟體。納稅人能做的是阻止銀行去冒償付能力或流動性風險
償付能力風險
縱觀歷史你會發現，為了解決特定問題採取的措施日後往往會造成剛大的問題。1907年的金融恐慌使美聯儲於1913年應運而生。美聯儲為銀行提供了安全保證：法定準備金的下降、公開市場買賣、壓低貸款利率，使得銀行快速的擴展信貸業務，最終導致了1929年的經濟危機。
防止銀行面臨清償能力風險的第一步就是防範資產泡沫的發生。限制美聯儲對市場利率的幹預可以使市場的信貸實現自然平衡。信貸規模的擴張會導致還款利息的上漲，進一步的借貸規模便會減小。
第二步就是逐漸提高銀行的法定準備金。最直接的方法是迫使銀行提高產權資本，另外一個比較受歡迎的方法是格雷戈裡•曼昆提出的，如果金融監管機構認為銀行資金不足，便可要求銀行增加可轉化為資金的或有債務。
第三步是沃爾克法則：限制銀行利用自身資本進行自營交易。允許銀行交易高達其資金的3%的規定讓我很不滿意，因為法規越明確就越難以實施。不久之後，銀行就會利用槓桿進行大規模交易，而且，這也給比例（3%）幅度增加敞開了大門。
流動性風險
正如之前所說的，流動性風險產生的主要原因是到期日的不匹配性。根據美聯儲的零利率政策，銀行可以付給通知存款者接近於零的利率，銀行可以用存款者的資金借貸或投資，這就為銀行創造了很大的利潤空間。這麼做會使銀行過度依賴於短期存款，是不值得提倡的。
如果投資機構1的短期存款平均為兩週，該機構將短期存款的資金用於平均為六年的投資；同樣水平的投資機構2的短期存款平均為兩週，進行回報週期為兩週的短期投資；機構3的存款週期為12個月，進行為期6年的投資。那麼機構1相對於機構2、3會面臨更大的流通性風險。
最簡單的方法是提高上述機構（依賴於短期存款）的法定準備金，這也會降低其在繁榮時期的信貸擴張速度。
存款保險
當一個了不起的主意變成一個壞主意。
存款保險在20世紀30年代被引入並挽回了美國銀行瀕臨滅絕的境地。由聯邦存款保險公司對各大銀行徵收存款保險。然而，這後來引發了道德危機。在聯邦存款保險公司的擔保下，存款者不必擔心銀行的清償能力。高風險的機構可以和那些經營良好、低風險的機構在同等的條件下競争。這無疑導致了更高的壞賬率，比如20世紀80年代的儲蓄和貸款危機。
聯邦存款保險公司在監管存款機構方面做得很好，但是卻不可以取代市場的作用。存款保險在經濟危機的時候起到了十分關鍵的作用，但是當危機結束之後，應該減少它的幅度，比如將最高保險金額設為兩萬美金或者賠付被保金額的90%。這就足以讓存款者謹慎選擇存款機構，並增加經營良好的存款機構的競争力。
影子銀行
不受監管的影子銀行曾兩次威脅到整個金融體系：1907年不受監管的投資信托基金和2007年的投資銀行。銀行法規和法定準備金的要求應該適用於所有涉及期限轉換的機構。
證券化
不動產證券化的盛行是引起1929年金融危機的首要因素，並且導致了最近的這次金融危機。證券化掩蓋了期限轉換的本質:長期資產來源於流動性的市場融資，並可以短線交易（類似於股票）。其中的問題存在於，在經濟危機市場缺少流動性的時候，就只剩下短線投資者和長期資產。上個世紀末，受監管的銀行為了規避準備金大規模施行不動產的證券化。抵押貸款證券化加劇了金融危機。
房利美和房地美
房利美成立於1938年，經濟大蕭條結束之際，促進了房地產市場的發展。1968年私有化，並在1970年收購了房地美—-為了提升其在房地產市場上的競争力。因受到政府的支持，房利美和房地美發展迅速，在2008年擁有或擔保約半數12美元萬億美元的住宅抵押貸款市場。房地產泡沫破裂之後，房利美和房地美被聯邦住房金融局的接管。為了增加國庫資金，國家債務限額提高到了8000億美元，其中美聯儲購買了12.5億美金的證券以支持按揭市場，降低抵押貸款利率。
房利美和房地美迄今已花費美國納稅人$1450億的救市成本，將繼續對金融市場的穩定和納稅人的錢包構成威脅。唯一的長期解決方案就是讓它破產，並拍賣它的資產。
結論
你不能有效地規範了銀行業，同時允許大部分金融業的繞過銀行法規。唯一的辦法就是對證券和其他大規模涉及期限轉換的機構施行同樣的法規和準備金要求，從而創造一個公平競争的環境。同樣重要的是，要通過提高準備金要求來防止銀行在納稅人資金的庇護下進行自營交易。
Preventing Future Banking Panics
To protect ourselves from future banking panics we need to understand the underlying causes. Panics are normally precipitated by an insolvency crisis, which then escalates into a liquidity crisis as depositors rush to withdraw their funds. The most common cause of a solvency crisis is the collapse of a stock market or property bubble, with a sharp fall in prices leaving banks exposed to write-downs. And the primary cause of asset bubbles is a rapid expansion in credit leading to inflation of asset values.
Banks are also particularly vulnerable to liquidity crises because of the nature of their business. Their major source of profits is from borrowing short and lending long, commonly referred to as maturity transformation (or maturity mis-match), where they make a healthy margin between long-term loan rates and short-term deposit rates.
Without maturity transformation, systemic banking panics would be extremely rare. Banks would call in short-term assets to meet their short-term obligations, with no need for the Federal Reserve to provide additional liquidity. The only remaining crises would be solvency-based.
Banks are protected by the federal government in two important ways:
1. Solvency is guaranteed by deposit insurance where the federal government underwrites bank liabilities to depositors; and
2. Liquidity is provided by the Federal Reserve discount window where banks can obtain additional liquidity in the event of a run.
The taxpayer effectively acts as a buffer to the banking system, absorbing losses which the banks cannot withstand, and providing additional liquidity as required. There is no way around this as collapse of the entire banking system would bring down the entire economy. What the taxpayer can do, however, is to discourage banks from taking unnecessary solvency or liquidity risks.
Solvency Risks
If we examine history we will find that measures introduced to solve a particular problem often end up causing far greater problems in the long run. The creation of the Federal Reserve in 1913, in response to the banking panic of 1907, provided a safety net for banks. The safety net enabled banks to take on more risk, with capital reserves levels falling sharply. And open market operations by the Fed enabled the rapid expansion of credit prior to the 1929 crash.
So the unintended consequence of measures taken to protect against future banking panics was to almost halve capital reserve ratios and facilitate the rapid expansion of bank credit through suppression of market interest rates.
The first step in protecting banks against solvency risk is to guard against future asset bubbles. Limiting Fed interference with market interest rates would provide a natural counter-balance to credit expansion. Expansion would cause interest rates to rise, thereby deterring further borrowing.
The second step is to gradually increase bank reserves. The direct route would be to force banks to raise additional equity capital. An appealing alternative proposed by Gregory Mankiw is to require banks to raise contingent debt that can be converted to equity if the financial regulator deems the bank to have insufficient capital.
The third step is the Volcker rule: to prevent banks from engaging in proprietary trading while enjoying the protection of the taxpayer's dollar. I am uncomfortable with the 3 percent rule, which allows banks to trade up to 3 percent of their capital. Rules are far easier to enforce when they are absolute. How long will it take the banks to find a way to leverage the 3 percent into a significant exposure? It also leaves the door open for later increases in the percentage limit.
Liquidity Risk
The primary cause of liquidity risk, as discussed earlier, is maturity mis-match. With the Fed's zero interest rate policy, banks pay close to zero interest on call deposits, netting them a handsome spread when they lend/invest that money in the market at longer maturity. This can lead to over-reliance on short-term funding and should be discouraged.
An institution that raises deposits with an average maturity of 2 weeks and invests these in loans with an average maturity of 6 years has far greater liquidity risk than an otherwise identical institution that invests in short-term financial assets with an average maturity of 2 weeks — or an institution that raises deposits with an average maturity of 12 months and invest in identical loans with a maturity of 6 years.
The easiest solution may be to increase capital reserve requirements for institutions who engage in short-term funding. That would also slow the rate of credit expansion during a boom.
Deposit Insurance
When too much of a good idea becomes a bad idea.
Deposit insurance was introduced in the 1930s and saved the US banking system from extinction. Administered by the FDIC, and funded by a levy on all banking institutions, deposit insurance, however, encourages moral hazard. Depositors need not concern themselves with the solvency of the bank where they deposit their funds so long as deposits are FDIC insured. High-risk institutions are able to compete for deposits on an equal footing with well-run, low-risk competitors. This inevitably leads to higher failure rates, as in the Savings & Loan crisis of the 1980s.
The FDIC does a good job of policing deposit-takers, but no regulator can substitute for market forces. Deposit insurance is critical during times of crisis, but should be scaled back when the crisis has passed. Either limit insured deposits to say $20,000 or only insure deposits to say 90% of value, where the depositor takes the first loss of 10%. That should be sufficient to keep depositors mindful as to where they bank. And restore the competitive advantage to well-run institutions.
Shadow Banking
Development of an unregulated shadow banking system has twice come close to bringing down the entire financial system: unregulated investment trusts in 1907 and investment banks in 2007. Banking regulations and capital reserve requirements should apply to all institutions who engage in large scale maturity transformation.
Securitization
Securitization of real estate assets was rife in the lead up to the crash of 1929 and again in the lead up to the latest financial crisis. Securitization often masks maturity transformation, where long-term assets are financed through liquid markets and traded on a short-term basis in much the same way as stocks. The problem is that liquidity tends to dry up during a crisis, leaving short-term investors with a long-term asset. Banks engaged in massive securitization in the last decade in order to circumvent capital reserve requirements. This exacerbated the financial crisis when the market for mortgage-backed securities (MBS) dissolved.
Fannie Mae and Freddie Mac
Fannie Mae was founded in 1938, towards the end of the Great Depression, to facilitate mortgage finance for home buyers and to stimulate the real estate market. Privatized in 1968, it was joined by Freddie Mac in 1970 — to foster increased competition in the home mortgage market. With an implicit government guarantee, the two thrived and by 2008 owned or guaranteed about half of the $12 trillion US residential mortgage market. Following the collapse of the real estate market both were placed under the conservatorship of the FHFA. The national debt ceiling had to be increased by $800 billion to allow for increased Treasury funding, while the Fed purchased $1.25 billion of mortgage-backed securities to support the MBS market and reduce mortgage rates.
Fannie Mae and Freddie Mac have so far cost US taxpayers $145bn in bail-out costs and will continue to pose a threat to the taxpayer purse and stability of financial markets. The only long-term solution is to break them up and sell them off — with the clear understanding that there will be no implicit federal guarantee.
Conclusion
The bottom line is that you cannot effectively regulate the banking industry while allowing large parts of the financial sector to bypass banking regulations. The only solution is to create a level playing field by imposing the same regulations and capital reserve requirements on the securitization industry and any other institution that engages in large scale maturity transformation. It is also vitally important that we control the expansion of credit, in part by increasing capital reserve requirements, and prevent banks from engaging in proprietary trading while under taxpayers protection.
I have not discussed bank's use of derivatives and when too-big-to-fail extends to non-banking entities, in the insurance sector or in general industry. These will be covered in a later paper.
本文翻譯由兄弟財經提供，
文章來源：http://www.incrediblecharts.com/economy/banking_panics.php