Is it true and an economy's aggregate demand curve shifts leftward or rightward by more than changes in initial spending because of the multiplier effect?

Yes, it is true that an economy's aggregate demand curve can shift leftward or rightward by more than the initial changes in spending due to the multiplier effect. When there is an increase in spending, it leads to a greater overall increase in aggregate demand as the initial spending circulates through the economy, prompting further consumption and investment. Conversely, a decrease in spending can lead to a more significant decrease in aggregate demand as the initial reduction also results in reduced income and spending by others. This magnification effect illustrates how initial changes in spending can have a compounding impact on overall demand.