The concept and types of aggregate supply curves

Aggregate supply refers to the total amount of goods and services that firms in an economy are willing and able to produce at a particular price level during a specific period.

Short-run aggregate supply (SRAS) curve

The SRAS curve slopes upwards from left to right. This indicates that as the general price level increases, firms are prepared to supply more output.

Types of SRAS curves:

• Price inelastic SRAS - The curve is steep, meaning that increases in the price level lead to only small rises in output.
• Price elastic SRAS - The curve is relatively flat, showing that output can increase significantly with rises in the price level.

Long-run aggregate supply (LRAS) curve

The LRAS curve is vertical, representing the economy's full productive potential where all resources are utilised efficiently. In the long run, changes in the price level do not affect the total output, as it is determined by the availability and productivity of resources rather than prices.

Factors causing shifts in short-run aggregate supply (SRAS)

Shifts in the SRAS curve occur due to changes in the costs of production.

Rightward shifts in SRAS

A rightward shift means that more output can be supplied at the same price level:

• Decreases in input prices - Lower costs for raw materials enable firms to produce more without raising prices.
• Changes in wage rates - If labour costs decrease, firms can afford to increase output.
• Changes in business taxes - Reduced taxation on firms decreases overall costs, allowing for greater supply.
• Changes in exchange rates - A stronger domestic currency makes imported inputs cheaper, boosting supply.
• Improvements in efficiency - Advances in processes or technology that reduce waste can increase output without additional costs.

Leftward shifts in SRAS

A leftward shift reduces the output supplied at the same price level:

• Increases in input prices - Rising costs for essentials like energy can force firms to cut back on production.
• Higher wage rates - Increases in labour costs raise overall expenses.
• Higher business taxes - Additional taxation burdens increase costs, limiting supply.
• Unfavourable exchange rates - A weaker domestic currency makes imports more expensive, raising input costs.
• Supply-side shocks - Unexpected events, like severe weather disrupting supply chains or geopolitical conflicts limiting resource access, can suddenly decrease aggregate supply.

Factors influencing long-run aggregate supply (LRAS)

The LRAS curve shifts due to changes in the economy's productive capacity, which is determined by the quantity and quality of factors of production.

Rightward shifts in LRAS

These enhancements increase the economy's maximum output, leading to potential economic growth as the vertical LRAS curve moves to the right:

• Advances in education and skills - Enhanced training schemes raise worker productivity.
• Demographic improvements - An influx of skilled workers expands the labour force and boosts capacity.
• Discovery of new resources - Finding additional natural assets increases available inputs for production.
• Healthcare advancements - Initiatives that improve public health reduce illness-related absences and extend working lives, enlarging the effective workforce.
• Regulatory reforms - Simplifying rules, such as easing business setup procedures, encourages more efficient operations.
• Increased competition - Stronger market rivalry pushes inefficient firms out, replacing them with more productive ones.
• Promotion of entrepreneurship - Incentives like grants for new businesses foster innovation and expand economic capacity.
• Enhanced factor mobility - Programmes that help workers retrain for different sectors reduce barriers to adapting the labour force.
• Foreign direct investment - Inflows of capital from abroad introduce new technology and methods, improving efficiency and maximum output.

Leftward shifts in LRAS

These declines reduce the economy's productive capacity, shifting the LRAS curve to the left and limiting maximum output:

• Depletion of resources - Exhaustion of key natural inputs restricts production possibilities.
• Loss of skilled labour - Emigration of qualified workers or inadequate training can shrink the effective workforce.
• Regulatory burdens - Excessive bureaucracy can hinder efficiency and innovation, reducing overall capacity.