Answer:
The comparison and contrast economically between the 1920s and the 1930s is significant. It is a comparison between: embracing American Exceptionalism (1920s, Coolidge-Harding) and rejecting American Exceptionalism (1930s, Hoover-Roosevelt); an adherence to the Great Experiment (1920s, Coolidge-Harding) and a denunciation of the Great Experiment (1930s, Roosevelt-Hoover).