Explanation:
In the short run, after the announcement of the United Kingdom's vote to leave the European Union, consumer confidence decreased significantly. This led to a decrease in consumption expenditure, which caused the aggregate demand curve to shift to the left. This shift is depicted by the movement of the economy from point A to point B in the graph. However, in the long run, when all prices are flexible, the economy adjust the aggregate supply curve can also shift. For example, if businesses are facing reduced demand for their products due to lower consumer confidence, they may lower their prices to attract customers. This can lead to a decrease in production costs and an increase in aggregate supply. Overall, in the long run, the economy can reach a new equilibrium point, where the aggregate demand and aggregate supply curves intersect at a lower level of output and prices. This new equilibrium reflects the adjustments made by businesses and the overall impact of the decrease in consumer confidence on the economy. It's important to note that the exact movements of the exact movements of the aggregate demand and aggregate supply curves in the long run depend on various factors, such as the magnitude of the initial shock, the flexibility of prices and wages, and other economic conditions.
Additionally, the long-run impacts of events like the United Kingdom's vote to leave the European Union can vary and are subject to ongoing analysis and research..