One reason why the Federal Reserve did not act to limit the decline of the money supply was regulation. At that time, the amount of credit the Federal Reserve could issue was limited by laws which required partial gold backing of that credit. By the late 1920s, the Federal Reserve had almost hit the limit of allowable credit that could be backed by the gold in its possession. This credit was in the form of Federal Reserve demand notes. Since a "promise of gold" is not as good as "gold in the hand", during the bank panics a portion of those demand notes were redeemed for Federal Reserve gold. Since the Federal Reserve had hit its limit on allowable credit, any reduction in gold in its vaults had to be accompanied by a greater reduction in credit. On April 5, 1933, President Roosevelt signed Executive Order 6102 making the private ownership of gold certificates, coins and bullion illegal, reducing the pressure on Federal Reserve gold.

Recent work from a neoclassical perspective focuses on the decline in productivity that caused the initial decline in output and a prolonged recovery due to policies that affected the labor market. This work, collected by Kehoe and Prescott, decomposes the economic decline into a decline in the labor force, capital stock, and the productivity with which these inputs are used. This study suggests that theories of the Great Depression have to explain an initial severe decline but rapid recovery in productivity, relatively little change in the capital stock, and a prolonged depression in the labor force. This analysis rejects theories that focus on the role of savings and posit a decline in the capital stock.

Another explanation comes from the Austrian School of economics. Theorists of the "Austrian School" who wrote about the Depression include Austrian economist Friedrich Hayek and American economist Murray Rothbard, who wrote America's Great Depression (1963). In their view and like the monetarists, the Federal Reserve, which was created in 1913, shoulders much of the blame; but in opposition to the monetarists, they argue that the key cause of the Depression was the expansion of the money supply in the 1920s that led to an unsustainable credit-driven boom. In the Austrian view it was this inflation of the money supply that led to an unsustainable boom in both asset prices (stocks and bonds) and capital goods. By the time the Fed belatedly tightened in 1928, it was far too late and, in the Austrian view, a significant economic contraction was inevitable. According to the Austrians, the artificial interference in the economy was a disaster prior to the Depression, and government efforts to prop up the economy after the crash of 1929 only made things worse. According to Rothbard, government intervention delayed the market's adjustment and made the road to complete recovery more difficult.

Marx saw recession and depression as unavoidable under free-market capitalism as there are no restrictions on accumulations of capital other than the market itself. In the Marxist view, capitalism tends to create unbalanced accumulations of wealth, leading to over-accumulations of capital which inevitably lead to a crisis. This especially sharp bust is a regular feature of the boom and bust pattern of what Marxists term "chaotic" capitalist development. It is a tenet of many Marxists groupings that such crises are inevitable and will be increasingly severe until the contradictions inherent in the mismatch between the mode of production and the development of productive forces reach the final point of failure. At which point, the crisis period encourages intensified class conflict and forces societal change.

Two economists of the 1920s, Waddill Catchings and William Trufant Foster, popularized a theory that influenced many policy makers, including Herbert Hoover, Henry A. Wallace, Paul Douglas, and Marriner Eccles. It held the economy produced more than it consumed, because the consumers did not have enough income. Thus the unequal distribution of wealth throughout the 1920s caused the Great Depression.

According to this view, the root cause of the Great Depression was a global over-investment in heavy industry capacity compared to wages and earnings from independent businesses, such as farms. The solution was the government must pump money into consumers' pockets. That is, it must redistribute purchasing power, maintain the industrial base, but re-inflate prices and wages to force as much of the inflationary increase in purchasing power into consumer spending. The economy was overbuilt, and new factories were not needed. Foster and Catchings recommended federal and state governments start large construction projects, a program followed by Hoover and Roosevelt.

Various countries around the world started to recover from the Great Depression at different times. In most countries of the world, recovery from the Great Depression began in 1933. In the U.S., recovery began in the spring of 1933. However, the U.S. did not return to 1929 GNP for over a decade and still had an unemployment rate of about 15% in 1940, albeit down from the high of 25% in 1933.

There is no consensus among economists regarding the motive force for the U.S. economic expansion that continued through most of the Roosevelt years (and the 1937 recession that interrupted it).

The common view among mainstream economists is that Roosevelt's New Deal policies either caused or accelerated the recovery, although his policies were never aggressive enough to bring the economy completely out of recession. Some economists have also called attention to the positive effects from expectations of reflation and rising nominal interest rates that Roosevelt's words and actions portended. However, opposition from the new Conservative Coalition caused a rollback of the New Deal policies in early 1937, which caused a setback in the recovery.