First, the global economy is unbalanced. That is, the rapid growth of savings in emerging market economies has led to huge current account surpluses and rapidly increasing official foreign exchange reserves in these countries in recent years. The huge reserve funds of these developing countries with immature financial markets flow into developed countries such as the United States, reducing the interest rates of the countries where the funds flow. In addition, the savings rate of developed countries (especially the United States and Britain) is very low, which will inevitably force developed countries to carry out financial innovation in order to obtain higher return on investment, especially to create very complex financial derivatives.

Second, the United States implements a loose monetary policy.

Third, the neo-liberal theory. The main defect of neoliberal economic growth model is that it relies too much on debt and inflation to promote demand.

Fourth, as the world currency, the US dollar monopolized the international monetary system. The hegemonic position of the dollar is the imbalance of the international monetary system.

The European debt crisis is partly due to excessive consumption in some countries in the euro zone, which makes the government unbearable and reduces the credibility of national bonds. The selling of the holders makes repayment difficult and leads to crisis.

The international financial crisis triggered by the US subprime mortgage crisis may also lead to the European debt crisis. It is not clear whether the European debt crisis is part of the evolution of the international financial crisis.