6. Use the following information to work Problems a & b given below. The following events have occurred at times in the history of the United States: (5 Marks) the world economy goes into an expansion. U.S. businesses expect future profits to rise. the government increases its expenditure on goods and services in a time of war or increased international tension. a. Explain for each event whether it changes short run aggregate supply, long-run aggregate supply, aggregate demand, or some combination of them. b. Explain the separate effects of each event on U.S. real GDP and the price level, starting from a position of long-run equilibrium