Causes of the Great Depression
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. Related to this explanation are those who point to debt deflation causing those who borrow to owe ever more in real terms.
Causes of the Great Depression
In the Cole-Ohanian model there is a slower than normal recovery which they explain by New Deal policies which they evaluated as tending towards monopoly and distribution of wealth. The key economic paper looking at these diagnostic sources in relation to the Great Depression is Cole and Ohanian's work. Cole-Ohanian point at two policies of New Deal: the National Industrial Recovery Act and National Labor Relations Act (NLRA), the latter strengthening NIRA's labor provision. According to Cole-Ohanian New Deal policies created cartelization, high wages, and high prices in at least manufacturing and some energy and mining industries. Roosevelts policies against the severity of the Depression like the NIRA, a "code of fair competition" for each industry were aimed to reduce cutthroat competition in a period of severe deflation, which was seen as the cause for lowered demand and employment. The NIRA suspended antitrust laws and permitted collusion in some sectors provided that industry raised wages above clearing level and accepted collective bargaining with labor unions. The effects of cartelization can be seen as the basic effect of monopoly. The given corporation produces too little, charges too high of a price, and under-employs labor. Likewise, an increase in the power of unions creates a situation similar to monopoly. Wages are too high for the union members, so the corporation employs fewer people and, produces less output. Cole-Ohanian show that 60% of the difference between the trend and realized output is due to cartelization and unions. Chari, Kehoe, McGrattan also present a nice exposition that's in line with Cole-Ohanian. .