a. The spending-Income multiplier reduces spending-income changes into larger changes in aggregate supply, causing cost-push Inflation. magnifies spending-income changes into greater changes in aggregate demand, causing demand-pull inflation. reduces spending-income changes into smaller changes in aggregate supply, causing demand-push inflation. magnifies spending-Income changes into smaller changes in aggregate demand, causing demand-pull inflation. b. According to mainstream economists, the usual cause of macroeconomic instability is the national debt. aggregate spending and its components. International trade disruptions. aggregate production and its components. c. According to mainstream economists, adverse aggregate supply factors can cause instability by alternately causing cost-push Inflation and recession. simultaneously causing cost-push Inflation and recession. causing cost-push inflation or recession. never causing cost-push Inflation and recession.