The Consumer (Demand) (Leaving Cert Economics): Revision Notes
The Consumer (Demand)

1. The economic role of consumers
Consumers play a crucial part in driving any economy forwards through their daily purchasing choices. When you decide to buy a coffee, download a streaming service, or purchase new clothes, you're participating in the economic system as a consumer.
Consumer spending decisions create demand for goods and services throughout the economy. This demand acts as a signal to businesses, telling them what products people want and how much they're willing to pay.
Your purchasing choices influence three key areas:
- Employment levels - When demand for products increases, companies need more workers to meet this demand
- Business investment - Strong consumer demand encourages firms to invest in new equipment and expand their operations
- Economic growth - Higher consumer spending drives overall economic activity upward
Positive incentives
These are rewards that encourage people to make certain purchasing decisions. Positive incentives make products more attractive by reducing their cost or increasing their value to consumers.
Common examples you'll encounter include:
- Discounts and sales that lower prices and encourage more purchases
- Government subsidies for electric cars that reduce prices and boost demand for environmentally-friendly vehicles
- Tax reliefs on childcare that reduce household costs and increase disposable income
Negative incentives
These are costs or penalties designed to discourage specific consumer behaviours. Negative incentives make products less attractive by increasing their cost or creating disadvantages.
Examples include:
- Carbon tax making fossil fuels more expensive to reduce consumption and encourage greener alternatives
- Sugar tax increasing the price of soft drinks to discourage unhealthy eating habits
- Higher insurance premiums that discourage risky behaviour by making it more costly
Case study: Ireland's plastic bag levy (2002)
Case Study: Ireland's Plastic Bag Levy Success
Ireland introduced a 15 cent tax on plastic bags in 2002, which successfully reduced their use by 90% in the first year. This demonstrates how effective a well-designed negative incentive can be in changing consumer behaviour quickly and dramatically.
2. Rational vs irrational consumers
The traditional assumption
Economic theory traditionally assumes consumers are rational - meaning they always make decisions that maximise their satisfaction (called utility) within their budget constraints. A rational consumer would always choose the option that gives them the most value for money.
Critiques of rational behaviour
However, behavioural economics research shows that consumers often behave irrationally. Several factors influence our decision-making beyond pure logic:
Factors Leading to Irrational Consumer Behaviour:
- Psychological influences such as ingrained habits, brand loyalty, social pressure from friends, and persuasive advertising
- Limited information - consumers may not know about cheaper or better alternatives available in the market
- Short-term focus - people often prioritise immediate satisfaction over long-term consequences, leading to overspending or poor financial decisions
Real-world examples of irrational behaviour
- Purchasing fast fashion items despite knowing their environmental impact, because the immediate satisfaction outweighs long-term concerns
- Paying premium prices for branded medicines when identical generic versions cost much less
3. Price elasticity of demand (PED)
Definition and importance
Price elasticity of demand measures how sensitive consumer demand is when prices change. Understanding PED helps explain why some price increases barely affect sales, while others cause demand to collapse.
Formula
Types of PED
Elastic demand (PED > 1): Demand responds strongly to price changes. This typically occurs with luxury goods and non-essential items where consumers can easily delay purchases or find alternatives.
Inelastic demand (PED < 1): Demand barely responds to price changes. This happens with necessities like petrol, cigarettes, and basic food items where consumers have few alternatives.
Unit elastic demand (PED = 1): Demand changes proportionally with price - a 10% price rise causes exactly a 10% fall in demand.
Worked Example: Calculating PED
If the price of coffee rises by 10% and demand falls by 20%:
Step 1: Apply the formula
Step 2: Insert the data
Step 3: Interpret the result This negative result shows the inverse relationship between price and demand, while the value of 2 (ignoring the minus sign) indicates elastic demand.
Uses of PED
Applications of Price Elasticity of Demand:
For individuals: Understanding which goods are price-sensitive helps with budgeting and spending decisions.
For firms: PED guides pricing strategies:
- If demand is inelastic, firms can raise prices to increase revenue
- If demand is elastic, firms might cut prices to boost sales volume
For government: Taxes work best on goods with inelastic demand (like petrol and cigarettes) because they generate stable revenue without dramatically reducing consumption.
4. Income elasticity of demand (YED)
Definition
Income elasticity of demand measures how responsive demand is to changes in consumer income levels.
Formula
Types of goods based on YED
Normal goods (YED > 0): Demand increases when income rises. Examples include clothes, electronics, and restaurant meals.
Inferior goods (YED < 0): Demand decreases when income rises, as people switch to better alternatives. Examples include instant noodles and bus travel.
Luxury goods (YED > 1): Demand rises more than proportionally with income. Examples include designer fashion and foreign holidays.
Worked Example: Calculating YED
If income rises by 5% and demand for holidays increases by 15%:
Step 1: Apply the formula
Step 2: Insert the data
Step 3: Interpret the result This positive result above 1 indicates holidays are a luxury good where demand grows rapidly as people become wealthier.
Uses of YED
Applications of Income Elasticity of Demand:
For individuals: YED helps predict how spending patterns might change as income increases or decreases.
For firms:
- Luxury brands expand operations when the economy grows and incomes rise
- Discount retailers prepare for growth when incomes fall
For government: YED helps predict demand for social housing and welfare services during economic downturns, and forecast tax revenue changes during periods of economic growth or recession.
5. Irish consumer spending patterns
The CSO Household Budget Survey provides valuable insights into how Irish households allocate their spending across different categories.
Major spending categories
Largest spending category: Housing, rent, and energy costs represent the biggest share of household budgets, reflecting Ireland's high accommodation costs.
Other significant areas: Food, transport, healthcare, and recreation form the other major spending categories.
Changing trends
Evolving Irish Consumer Spending Patterns:
Rising trends: Technology spending (streaming services, smartphones), childcare costs, and education expenses are growing areas of household expenditure.
Declining trends: Spending on tobacco and alcohol is falling as health awareness increases and government policies discourage consumption.
Current data example
2023 CSO figures showed Irish households spend over 30% of their income on housing and utilities, reflecting the ongoing challenges with high rental costs and energy prices in Ireland.
Exam tips
Essential Exam Strategy for Consumer Demand Questions:
- Always begin elasticity questions by stating the relevant definitions for PED, YED, and rational behaviour
- For calculation questions, follow this structure:
- Show the formula clearly
- Insert the data into the formula step by step
- State whether demand is elastic or inelastic and explain what this means
- Use real Irish examples such as the plastic bag levy, carbon tax, and rising housing costs to demonstrate understanding
- In evaluation questions, balance theory with reality by discussing both rational economic assumptions and irrational behavioural factors
- When discussing consumer spending patterns, quote current CSO data to show knowledge of up-to-date trends
Summary
Key Points to Remember:
- Consumer demand drives economic activity and signals to firms what to produce
- Both positive and negative incentives effectively influence consumer choices and behaviour
- While economic theory assumes rational behaviour, consumers often make irrational decisions due to psychological factors and limited information
- PED measures price sensitivity and helps individuals, firms, and governments make informed decisions about pricing and taxation
- YED measures income sensitivity and explains how spending patterns change with economic growth or recession
- Irish consumers allocate most spending to housing, food, and transport, with technology and childcare representing growing expense categories
- Understanding real-world data and examples enhances comprehension of consumer behaviour theory
Remember!
Essential Takeaways:
- Consumer choices drive the entire economy - your spending decisions influence what gets produced and how many jobs are created
- Incentives work - both rewards and penalties can effectively change consumer behaviour, as shown by Ireland's plastic bag levy success
- People aren't always rational - psychological factors often override pure economic logic in purchasing decisions
- Elasticity concepts are practical tools - PED and YED help predict how consumers respond to price and income changes
- Irish examples strengthen exam answers - use current CSO data and local case studies to demonstrate applied understanding