Economics - Topic 3 - Price Determination

Chains of Analysis + Real Life Examples

1. How does an increase in consumer income affect demand for normal goods?

Point: Higher disposable income can increase demand for normal goods.

Because: Consumers have greater purchasing power, allowing them to afford more goods and services.

Leads to: Increased demand at each price, shifting the demand curve rightwards.

Therefore: Equilibrium price and quantity increase, assuming supply remains unchanged.

Evaluation: Depends on the income elasticity of demand (YED); necessities generally respond less than luxury goods.

2. How does an increase in consumer income affect demand for inferior goods?

Point: Rising incomes can reduce demand for inferior goods.

Because: Consumers can afford higher-quality alternatives as their purchasing power increases.

Leads to: Reduced demand at each price, shifting the demand curve leftwards.

Therefore: Equilibrium price and quantity fall, assuming supply remains unchanged.

Evaluation: Depends on consumer preferences and how strongly the good is considered inferior.

3. How does advertising increase demand for a product?

Point: Successful advertising can increase consumer demand.

Because: Advertising raises awareness and can improve consumers' perceptions of a product.

Leads to: More consumers being willing to purchase the good at each price.

Therefore: Demand shifts rightwards, potentially increasing equilibrium price and quantity.

Evaluation: Depends on advertising effectiveness and the availability of competing products.

4. How can price inelastic demand increase a firm's revenue following a price rise?

Point: Firms selling price-inelastic goods may increase total revenue by raising prices.

Because: Consumers are relatively unresponsive to price changes, often due to necessity or a lack of close substitutes.

Leads to: A proportionately smaller decrease in quantity demanded than the percentage increase in price.

Therefore: Total revenue increases because the higher price outweighs the loss of sales.

Evaluation: Demand may become more elastic in the long run as consumers find substitutes.

5. Why can reducing prices increase revenue when demand is price elastic?

Point: A price reduction can increase total revenue when demand is elastic.

Because: Consumers are highly responsive to price changes, particularly when substitutes are available.

Leads to: A proportionately larger increase in quantity demanded than the percentage decrease in price.

Therefore: Total revenue increases as additional sales outweigh the lower price per unit.

Evaluation: Higher revenue does not necessarily mean higher profit if costs increase substantially.6. How does the availability of substitutes affect PED?

6. How does the availability of substitutes affect PED?

Point: Goods with more close substitutes tend to have more price-elastic demand.

Because: Consumers can easily switch to alternative products following a price increase.

Leads to: A relatively large fall in quantity demanded when the original product becomes more expensive.

Therefore: Firms have less ability to increase prices without losing substantial sales.

Evaluation: Strong brand loyalty may reduce consumers' willingness to switch.

7. How does a high positive YED affect demand during economic growth?

Point: Luxury goods with high positive YED benefit disproportionately from rising incomes.

Because: Consumers spend more on discretionary products as disposable income increases.

Leads to: A proportionately larger increase in demand than the percentage increase in income.

Therefore: Demand shifts rightwards significantly, potentially increasing firms' revenue.

Evaluation: During recessions, demand for these products may fall disproportionately.

8. How does a rise in the price of a substitute affect demand?

Point: An increase in the price of a substitute can increase demand for another product.

Because: Consumers switch towards the relatively cheaper alternative.

Leads to: Demand for the alternative good shifting rightwards.

Therefore: Its equilibrium price and quantity increase, assuming supply remains unchanged.

Evaluation: Depends on the closeness of substitutes, measured by positive XED.

9. How does a rise in the price of a complementary good affect demand?

Point: Higher prices of complementary goods can reduce demand for related products.

Because: Consumers often purchase the two goods together, increasing the overall cost of consumption.

Leads to: Reduced demand for the complementary product, shifting its demand curve leftwards.

Therefore: Its equilibrium price and quantity may fall.

Evaluation: Depends on the strength of complementarity, measured by negative XED.

10. How does an increase in production costs affect market supply?

Point: Rising production costs can reduce market supply.

Because: Higher wages, energy or raw material costs reduce profitability at existing prices.

Leads to: Firms becoming less willing or able to supply goods at each price, shifting supply leftwards.

Therefore: Equilibrium prices rise and quantities fall, assuming demand remains unchanged.

Evaluation: Depends on whether firms can absorb costs or improve productivity.

11. How does technological advancement increase market supply?

Point: Improved technology can increase market supply.

Because: More efficient production methods reduce costs per unit of output.

Leads to: Firms being willing to supply more at each price, shifting supply rightwards.

Therefore: Equilibrium prices fall and quantities increase, assuming demand remains unchanged.

Evaluation: Depends on the cost of adopting technology and how widely it is implemented.

12. How can favourable weather conditions increase agricultural supply?

Point: Favourable weather can increase the supply of agricultural products.

Because: Improved growing conditions increase crop yields and reduce production losses.

Leads to: Greater quantities available at each price, shifting the supply curve rightwards.

Therefore: Equilibrium prices fall while quantities traded increase.

Evaluation: Depends on storage capacity, transport infrastructure and global demand.

13. Why can price-inelastic supply lead to large price increases?

Point: Price-inelastic supply can magnify price increases following rising demand.

Because: Producers cannot quickly expand output due to capacity constraints or lengthy production periods.

Leads to: Greater competition among buyers for a limited increase in available goods.

Therefore: Equilibrium prices rise substantially while quantity increases only slightly.

Evaluation: Supply may become more elastic in the long run as firms invest in additional capacity.

14. How does spare capacity increase price elasticity of supply?

Point: Firms with spare capacity tend to have more price-elastic supply.

Because: They can increase production using existing machinery and workers.

Leads to: A relatively large increase in quantity supplied when market prices rise.

Therefore: Supply responds more strongly to price incentives, potentially limiting price increases after demand rises.

Evaluation: Depends on whether firms can obtain additional labour and raw materials.

15. How does excess demand restore market equilibrium?

Point: Excess demand creates upward pressure on market prices.

Because: Quantity demanded exceeds quantity supplied at the existing price.

Leads to: Consumers competing for limited products, encouraging sellers to raise prices.

Therefore: Quantity demanded contracts and quantity supplied expands until equilibrium is restored.

Evaluation: Price adjustment may be slow if prices are fixed by contracts or government controls.

16. How does excess supply restore market equilibrium?

Point: Excess supply creates downward pressure on prices.

Because: Producers supply more goods than consumers are willing to purchase at the current price.

Leads to: Firms reducing prices to sell unsold inventories.

Therefore: Quantity demanded expands and quantity supplied contracts until equilibrium is restored.

Evaluation: Firms may initially store excess stock rather than immediately reducing prices.

17. How can increased demand for electric vehicles affect demand for lithium?

Point: Higher demand for electric vehicles can increase demand for lithium.

Because: Lithium is an important input in many electric-vehicle batteries.

Leads to: Increased EV production raising manufacturers' derived demand for lithium.

Therefore: Lithium demand shifts rightwards, potentially increasing its equilibrium price and quantity.

Evaluation: Depends on battery technology and the development of substitutes for lithium.

18. How can an increase in beef prices affect other markets?

Point: Changes in beef prices can influence demand for related goods.

Because: Consumers may switch from beef to substitute products such as chicken.

Leads to: Increased demand for chicken, shifting its demand curve rightwards.

Therefore: Chicken prices and quantities may rise, illustrating the interrelationship between markets.

Evaluation: Depends on cross elasticity of demand and consumers' dietary preferences.

19. How can an increase in demand for coffee affect demand for coffee cups? (Joint demand)

Point: Increased demand for one good can increase demand for a jointly demanded good.

Because: Coffee and disposable coffee cups are often used together.

Leads to: More coffee purchases increasing demand for cups.

Therefore: Demand for cups shifts rightwards, potentially increasing their equilibrium price and quantity.

Evaluation: Depends on whether consumers use disposable or reusable cups.

20. How can rising demand for biofuels affect food prices? (Composite demand)

Point: Greater demand for biofuels may increase food prices.

Because: Agricultural crops such as maize can be used for both food and biofuel production.

Leads to: Increased biofuel demand raising the total demand for maize.

Therefore: Maize prices may rise, increasing food production costs.

Evaluation: Depends on the availability of alternative crops and agricultural supply elasticity.

21. How can increased beef production affect the market for leather? (Joint supply)

Point: An increase in beef production may increase leather supply.

Because: Meat and animal hides are jointly produced from cattle.

Leads to: More cattle being processed, increasing the availability of hides for leather production.

Therefore: Leather supply shifts rightwards, potentially reducing its equilibrium price.

Evaluation: Depends on demand for hides and producers' ability to process them.

Section 2 - Real Life Examples

Give a real-world example of falling supply increasing prices - Global Cocoa Shortage

Global cocoa production fell 12.9% in 2023/24, contributing to a major supply shortage. London cocoa futures prices rose approximately 66% between October and December 2024.

Application: Falling supply → leftward supply shift → higher equilibrium prices.

Evaluation: The increase depends on demand and the ability of farmers to expand production.

Give an example of inelastic supply contributing to price increases - Global Coffee Prices

The FAO reported that world coffee prices increased 38.8% in 2024, largely due to adverse weather in major producing countries.

Application: Poor harvests reduce supply, while coffee production cannot expand quickly → larger price increases.

Evaluation: Supply may become more elastic in the long run as farmers invest in production.

Give a real-world example of derived demand - Electric Vehicle Demand

The International Energy Agency reported that global electric car sales exceeded 20 million in 2025, accounting for around 25% of new car sales.

Application: Greater EV production increases derived demand for battery inputs, including lithium.

Evaluation: Depends on battery technology and whether lithium substitutes become commercially viable.

Give an example of agricultural supply responding to production conditions - UK Wheat Production

UK wheat production increased by 7.3% to almost 12 million tonnes in 2025, largely due to an increase in harvested area despite lower average yields.

Application: Greater harvested area increases available output, potentially shifting market supply rightwards.

Evaluation: Market prices also depend on global supply and demand conditions.

Give an example of using price increases to reduce consumption - Scotland's Alcohol Pricing

Scotland increased its minimum alcohol price from 50p to 65p per unit in September 2024, aiming to reduce harmful consumption.

Application: Higher minimum prices encourage consumers to reduce quantity demanded. The impact depends on PED.

Evaluation: Consumers with strongly price-inelastic demand may reduce consumption relatively little.

Give an example of rising input costs affecting consumer prices - UK Chocolate Prices

UK chocolate prices were 17% higher in November 2025 than a year earlier, partly reflecting global cocoa supply disruptions. (Cholocate frogs from 10p to over £1.50

Application: Higher cocoa costs → reduced supply of chocolate at existing prices → upward pressure on equilibrium prices.

Evaluation: The extent to which costs are passed on depends on competition and price elasticity of demand.