对危机提出了各种原因，专家们对特定问题提出不同的看法。这场危机的直接原因是美国的房地产周期和相关的次级抵押贷款违约率的上升，这使许多金融机构的巨额损失和信贷市场的投资者信心动摇了。然而，尽管次贷危机引发了这场危机，但美国抵押贷款市场的发展只是一个更大和更具包容性的信贷繁荣的一个方面，其影响超越了抵押贷款市场，影响了许多其他形式的信贷。这个更广泛的信贷繁荣方面包括承销标准普遍下降，贷款监督由投资者和评级机构的故障，增加依赖复杂和不透明的信用工具，证明了脆弱的压力下，和冒险的异常低的补偿。信贷繁荣的突然终结带来了广泛的财政和经济后果。金融机构已经看到他们的资本因亏损和减记而枯竭，他们的资产负债表被复杂的信贷产品和其他不确定的非流动资产所堵塞。信用风险上升和强烈的风险厌恶情绪推动信用利差到前所未有的水平，以及资产证券化市场，除了有政府担保的抵押贷款证券，已经关闭了。高度的系统性风险、资产价值下降和信贷紧缩反过来又对企业和消费者信心造成沉重打击，并导致全球经济活动急剧放缓。损失，损失的产量，失去的工作，和失去的财富，已经是实质性的。
英国德里论文代写:房地产周期
Various causes have been proposed for the crisis, with experts placing different weights upon particular issues. The proximate cause of the crisis was the turn of the housing cycle in the United States and the associated rise in delinquencies on subprime mortgages, which imposed substantial losses on many financial institutions and shook investor confidence in credit markets. However, although the subprime debacle triggered the crisis, the developments in the U.S. mortgage market were only one aspect of a much larger and more encompassing credit boom whose impact transcended the mortgage market to affect many other forms of credit. Aspects of this broader credit boom included widespread declines in underwriting standards, breakdowns in lending oversight by investors and rating agencies, increased reliance on complex and opaque credit instruments that proved fragile under stress, and unusually low compensation for risk-taking. The abrupt end of the credit boom has had widespread financial and economic ramifications. Financial institutions have seen their capital depleted by losses and write downs and their balance sheets clogged by complex credit products and other illiquid assets of uncertain value. Rising credit risks and intense risk aversion have pushed credit spreads to unprecedented levels, and markets for securitized assets, except for mortgage securities with government guarantees, have shut down. Heightened systemic risks, falling asset values, and tightening credit have in turn taken a heavy toll on business and consumer confidence and precipitated a sharp slowing in global economic activity. The damage, in terms of lost output, lost jobs, and lost wealth, is already substantial.
