Through-out the history of the United States, there have been many bank panics starting with the first one in 1819. I use important data from bank panics which happened prior to 1934 to shed light on the most recent Panic of 2007. This data analysis will not only be important to explain the Panic of 2007, but will be essential to help provide insights to what can be done to remedy the situation. Even in 2012, the United States is still feeling the impact of what happened in 2007. Therefore by understanding history and analyzing the past, solutions to prevent future panics can be implemented.

銀行恐慌現象的探討一直都廣受研究金融危機與系統性風險等領域的經濟學者所青睞，而銀行擠兌潮更經常被視為導致銀行恐慌的主因之一。由於金融全球化已是時勢所趨，因此金融危機的蔓延更加受到學術界重視。Allen and Gale (2000)建構出不同型態的銀行同業拆借市場(Interbank market)，並以此為基礎進一步探討在最佳風險分攤的前提之下，銀行與消費者如何決定其投資與消費的最佳資源配置。 本文的基本架構係基於Allen and Gale (2000)所提出的經濟模型，配合存款保險制度的導入，嘗試驗證他們所提出的最佳資源配置是否仍然成立。而本文的結果證實政府實施存款保險制度，銀行與消費者仍然可以得到他們在投資與消費的最佳配置，即使在完美與不完美的銀行同業拆借市場，其結果仍然成立。另外本文也嘗試對存款保險制度是否能有效預防銀行恐慌與其蔓延作出驗證。其結果證實提高存款保險稅率後，銀行擠兌潮的發生需要較高的不可預期流動性需求。換言之，存款保險制度有效提高了銀行倒閉門檻。而對於預防透過銀行同業拆借市場所衍生的金融危機蔓延，存款保險制度的有效性也在本文中獲得證實。 然而存款保險制度並非具絕對優勢，過多則損害消費者的預期效用。因此本文將銀行倒閉風險機率納入模型，利用軟體模擬消費者預期效用極大化條件下的最適存款保險稅率。並且進一步證實，長期資產到期日清算與到期前清算，其兩者報酬率之間的利差愈大，存款保險最適稅率須同步增加，才能使消費者效用最大。另外我們也證實存款保險制度能夠提高社會福利水準與降低銀行倒閉風險。 / Bank panic serves as a favored subject for economists who engage in researches of financial crisis and systematic risk. Because financial liberalization and globaliza-tion have been inevitable, economic scholars have regarded financial contagion. Allen and Gale (2000) established different interbank market structures to achieve the first-best allocation of banks’ investment portfolio and depositors’ consumptions. In this paper, we try to confirm Allen and Gale’s first-best allocation when the deposit insurance is implemented, and we obtain the same consequence as well. Be-sides, we also approve that occurrence of a bank run must accompany by a high level of unexpected liquidity shock if the deposit insurance exists. In other words, it raises the threshold of bankruptcy. Therefore, the deposit insurance is feasible to avert bank panic. With regard to the contagion effect, the deposit insurance undoubtedly de-creases its negative influence because financial interdependence between different financial sectors will be attenuated by imposing a deposit-insurance tax on depositors. The deposit insurance, however, is not constantly superior due to the depositors’ loss in consuming utility. We achieve the optimal deposit-insurance tax rate by intro-ducing probability of bank’s bankruptcy, and find that the optimal tax rate may be raised, so as to boost consumers’ utility if return spread between early and late with-drawn long assets keeps higher. We also testify that the deposit insurance can enhance the social welfare and decrease the incidence of bankruptcy.