Current mainstream theories may be broadly classified into two main points of view. The first are the demand-driven theories, from Keynesian and institutional economists who argue that the depression was caused by a widespread loss of confidence that led to drastically lower investment and persistent underconsumption. The demand-driven theories argue that the financial crisis following the 1929 crash led to a sudden and persistent reduction in consumption and investment spending, causing the depression that followed.[2] Once panic and deflation set in, many people believed they could avoid further losses by keeping clear of the markets. Holding money therefore became profitable as prices dropped lower and a given amount of money bought ever more goods, exacerbating the drop in demand.
Second, there are the monetarists, who believe that the Great Depression started as an ordinary recession, but that significant policy mistakes by monetary authorities (especially the Federal Reserve) caused a shrinking of the money supply which greatly exacerbated the economic situation, causing a recession to descend into the Great Depression.[3] Related to this explanation are those who point to debt deflation causing those who borrow to owe ever more in real terms.
