Economists are callg it the adverse feedback loop, it is basically a situation where things start somewhere as with morgage securitization in the USA, and then spread in ahost of different ways through the economy in the USA and in ahost of other economies in interrelated fashion, compounding and worsening the original problem at every turn and every few months. This makes it harder to control and makes whatever steps that look aggressive at the time they are taken, become modest at the next turn in a few months. In February 2009, job losses of about 500,000 a month, and falling corporate profits create loan defaults, which hurt banks beyonfd the original mortgage problems. The banks falling stock prices along with loan defaults make it harder for them to raise capital and more reluctant to lend. All this cuts into spending on cars, factory equipment and other investment, feeding the cycle of job cuts and falling profits.