How demand varies with price and its determinants

Demand refers to the quantity of a good or service that consumers are willing and able to purchase at different price levels over a specific period. For normal goods, which are most everyday items, demand behaves in a predictable way in response to price changes.

Relationship between demand and price

Demand typically follows an inverse relationship with price. As the price of a good decreases, the quantity demanded increases because it becomes more affordable and attractive to buyers. Conversely, if the price rises, the quantity demanded decreases as consumers may seek cheaper alternatives or reduce their purchases.

Key determinants of demand

Several factors influence the overall level of demand for a product, beyond just its own price. These can cause the entire demand curve to shift.

These factors include:

• Consumer incomes - Higher incomes generally increase demand for normal goods, as people have more money to spend.
• Prices of substitute goods - If the price of a close alternative rises, demand for the original good may increase (e.g., if tea becomes more expensive, demand for coffee might grow).
• Prices of complementary goods - A fall in the price of a related good can boost demand (e.g., cheaper printers increase demand for ink cartridges).
• Population size and structure - A larger or younger population can raise demand for certain products, like toys or technology.
• Fashion and taste - Changing trends can make products more desirable, increasing demand.
• Advertising and promotion spending - Effective marketing campaigns can raise awareness and appeal, leading to higher demand.

How supply varies with price and its determinants

Supply is the quantity of a good or service that producers are willing and able to offer for sale at different price levels over a specific period. Businesses aim to maximise profits, so their supply decisions are closely tied to market prices.

Relationship between supply and price

Supply has a direct relationship with price. When the price of a good increases, producers are more willing to supply larger quantities because it becomes more profitable to do so. If the price falls, they supply less, as lower returns may not cover their costs.

Key determinants of supply

Various factors affect the overall supply of a product, independent of its price. These can lead to shifts in the entire supply curve.

These factors include:

• Costs of production - Rising expenses, such as higher labour wages, reduce supply as it becomes less profitable.
• Government taxes - Taxes on producers increase their costs, decreasing supply.
• Government subsidies - Financial support from the government lowers costs, encouraging more supply.
• Weather conditions and natural factors - Adverse events, like floods, can disrupt production and reduce supply.
• Advances in technology - Innovations that make production more efficient lower costs and increase supply.

The concept of equilibrium price

Equilibrium price is the market price at which the quantity demanded by consumers exactly matches the quantity supplied by producers. It represents a balance in the market where there is no tendency for the price to change.

How equilibrium is determined

The equilibrium price occurs at the intersection point of the demand and supply curves on a graph. At this point, the market clears, meaning all goods produced are sold, and all consumer demand is satisfied without shortages or surpluses.

How changes in determinants shift demand and supply curves

When determinants of demand or supply change, it does not just affect movement along the existing curves but creates entirely new curves. These shifts alter the equilibrium price and quantity in the market.

Shifts in the demand curve

• Rightward shift (increase in demand) - Occurs when a determinant boosts demand, such as rising consumer incomes. For instance, if average incomes grow, demand for laptops might increase, shifting the demand curve to the right.
• Leftward shift (decrease in demand) - Happens if a determinant reduces demand, like a shift in tastes away from a product, moving the curve left.

Shifts in the supply curve

• Rightward shift (increase in supply) - Results from factors that make production easier or cheaper, such as new technology. This shifts the supply curve right.
• Leftward shift (decrease in supply) - Caused by factors that hinder production, like poor weather affecting crop yields. For example, a frost damaging apple orchards would shift the supply curve left.

Market imbalances and price adjustments

Markets do not always operate at equilibrium. When the current price is above or below the equilibrium level, imbalances occur, prompting automatic adjustments through market forces.

Types of market imbalances

• Excess supply (surplus) - If the price is set above the equilibrium, suppliers offer more than consumers want to buy, leading to unsold stock. Suppliers respond by lowering prices to clear inventory, moving the market back towards equilibrium.
• Excess demand (shortage) - If the price is below the equilibrium, consumers demand more than suppliers provide, causing stock to run out quickly. Suppliers can then raise prices to increase profits and encourage more production, restoring balance.