When the marginal propensity to import and marginal propensity to save are smaller, the flatter will be the ZZ line and a given change in government spending (G) will have a smaller effect on domestic output.What is the ZZ line?The ZZ line shows equilibrium GDP when changes in spending are equal to changes in output. It is a 45-degree line on the income-expenditure graph. The income-expenditure graph is a graph that shows the relationship between GDP (output) and aggregate expenditures in the economy. When the marginal propensity to import and marginal propensity to save are small, a given change in government spending (G) will have a smaller effect on domestic output because of the flatter ZZ line. If there is a rise in government spending (G), aggregate demand (AD) will rise, which will cause a shift in the aggregate demand curve. However, because of the smaller marginal propensity to save and the smaller marginal propensity to import, the rise in AD will not translate into as significant an increase in output as if the marginal propensity to save and import were higher. As a result, a given change in government spending (G) will have a smaller effect on domestic output.