Aggregate Demand and Supply
High School
Definition
A model of the whole economy showing total spending (aggregate demand) and total output (aggregate supply). Their interaction helps explain national output, employment, and the price level.
Worked examples
During the 2008 financial crisis, consumer spending and business investment fell sharply, shifting aggregate demand left and causing a recession.
When total spending drops, AD shifts left, reducing both output and employment nationwide.
A drought destroys crops, reducing the economy's ability to produce goods and shifting aggregate supply left, raising prices and lowering output.
Supply shocks shift AS, changing the price level and real GDP in the opposite direction from demand shifts.
Common mistakes
- Aggregate demand is the same as demand for a single product → Aggregate demand is total spending across the entire economy AD sums spending on all goods and services, not just one market.
- Higher prices always mean the economy is growing → Higher prices can result from falling aggregate supply, which reduces output Stagflation shows prices rising while output falls when AS shifts left.
- Aggregate supply only depends on labor availability → Aggregate supply depends on labor, capital, technology, and resources AS reflects the economy's full productive capacity, not just workers.
Where you'll use it next
You'll apply AD-AS when studying business cycles, inflation, unemployment, fiscal and monetary policy, and how governments respond to recessions and booms in economics courses.
See also
Supply and DemandFiscal PolicyMonetary PolicyUnemployment and InflationMeasuring Economic PerformanceBusiness Cycle
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026