Why does a business cycle diagram serve as a forecasting model​

I think it's because shows how the economy is performing and when the economy is not performing well.

apart from being against desegregation, governor of georgia eugene talmadge opposed as well to the work progress administration, an ambitious program of the "new deal" created by president franklin d. roosevelt to overcome the great depression after world war i. talmadge disagreed with welfare spending, job training and organized labor. according to his ideas, he thought the government was spending too much money on this, and he wasn't willing to accept a wage higher than georgia's lower average wage. besides, talmadge strongly opposed to the "new deal" as he thought it had communist ideas.