Today's theory can be roughly divided into two main viewpoints and some heretical viewpoints. The first is demand-driven theory, especially Keynesian economic theory, but it also includes the collapse of international trade pointed out by some people. Financial economists of those financial institutions also point out insufficient consumption and excessive investment (leading to financial bubbles), illegal behavior of bankers and industrialists, and incompetence of government officials. The consensus view is that a large loss of confidence leads to a sudden decrease in consumption and investment expenditure. Once panic and inflation start, many people think they can make more money by [clearing the market], because lower prices will make the same money buy more goods, which will aggravate the reduction of demand.