Final answer:
The precise amount by which aggregate demand will shift cannot be determined from the given information due to the complexities and uncertainties involved in real-world economic conditions and policy impacts.
Step-by-step explanation:
The amount by which aggregate demand will shift cannot be precisely determined from the information provided. In economic theory, shifts in aggregate demand are affected by various factors, including fiscal policies, consumer confidence, and external economic shocks. The descriptive economic scenarios outlined suggest that while it is simple to depict a shift in aggregate demand within an AD/AS diagram, exact outcomes in the real economy are uncertain due to unknowns regarding the actual level of potential GDP, the precise impact of fiscal policy changes, and the unpredictable state of the economy at given times.
For example, during the financial crisis, the rapid decline in certain sectors made it challenging to measure how the economy was reacting. Meanwhile, figures indicating a rebound to potential GDP post an aggregate demand shift suggest that aggregate demand affects price levels and can rebound due to changes in other economic variables like unemployment impacting wages, which in turn affect costs and short-run aggregate supply.