A-Level Economics: Aggregate Demand and Supply

The AD/AS model is the macro workhorse the DfE subject content names explicitly: students must "use the aggregate demand/aggregate supply model and data to understand why supply-side and/or demand-side policies may be seen as appropriate". This quiz builds command of the model itself, entirely in words.

The aggregate demand questions cover the C+I+G+(X−M) decomposition and its behavioural determinants: business confidence and interest rates driving investment, the wealth effect linking asset prices to consumption, and the exchange-rate channel — an appreciation cutting net exports and shifting AD left. The multiplier is tested computationally: government spending up £50 billion with an MPC of 0.8 producing a £250 billion income rise through k = 1/(1−MPC) = 5, plus the leakage logic — a higher marginal propensity to import shrinking the multiplier — and the full leakage trio (savings, taxes, imports).

The supply side distinguishes the curves precisely: cost shocks (oil prices, nominal wages) shifting short-run aggregate supply left, and the two long-run views the specification requires side by side — the classical vertical LRAS where demand shocks move only prices, and the Keynesian curve whose horizontal range lets demand expansion raise output without inflation while spare capacity lasts. A rightward LRAS shift is read correctly as higher potential output with downward price pressure.

Shock analysis ties the model together, tested from both the demand and supply directions. Each explanation traces the full transmission — shock, curve shift, new equilibrium in output and prices — the exact chain-of-reasoning structure that AD/AS essay questions are marked on, and the foundation the fiscal, monetary and supply-side policy quizzes in this category build upon.

• Decompose aggregate demand and explain each component's determinants
• Calculate multiplier effects from the MPC and explain how leakages shrink them
• Distinguish SRAS shifts from LRAS shifts and their causes
• Contrast classical and Keynesian LRAS views and their policy implications
• Trace demand and supply shocks through to output and price outcomes

Aligned to "The determination of output, employment and prices" area of the DfE's GCE A level economics subject content: the circular flow of income, expenditure and output, and aggregate demand and aggregate supply.