Which statements about the Keynesian approach is correct? The Keynesian approach, with its focus on aggregate demand and sticky prices, has proved useful in understanding how the economy fluctuates in the short run, but not why recessions and cyclical unemployment occur. The Keynesian approach, with its focus on aggregate demand and sticky prices, has proved useful in understanding how the economy fluctuates in the short run, and why recessions and cyclical unemployment occur. The Keynesian approach, with its focus on aggregate demand and sticky prices, has not proved useful in understanding how the economy fluctuates in the short run, or why recessions and cyclical unemployment occur. The Keynesian approach, with its focus on aggregate demand and sticky prices, has proved useful in understanding why recessions and cyclical unemployment occur, but not how the economy fluctuates in the short run.