Price elastic demand
|PED| > 1. Demand changes by a larger percentage than price. A 10% price rise with PED −2 would be associated with an approximate 20% fall in quantity demanded, other things equal.
Cambridge International A Level Business · Topic 8.1
Marketing Analysis
Marketing analysis helps managers understand demand, develop suitable products and estimate future sales. This topic brings together quantitative tools such as elasticity and moving averages with judgement-based approaches such as test marketing and qualitative forecasting.
ElasticityProduct developmentResearch & developmentSales forecastingWorked calculations
What you need to master
You should be able to calculate and interpret price, income and promotional elasticity; assess the process and risks of new product development; explain the role of research and development and intellectual-property protection; calculate moving averages; and evaluate different approaches to sales forecasting in a business context.
Exam focus: calculations earn marks only when they are interpreted. After finding an elasticity, moving average or forecast, explain what the result means for pricing, promotion, production, staffing, finance or strategy.
Elasticity
Market analysis and sensitivity of demand
Market analysis examines market conditions, including market size and the factors that influence demand. Managers are interested not only in whether price, income or promotion affect demand, but in how strongly demand reacts. Elasticity measures this sensitivity while assuming other relevant factors remain unchanged.
Elastic response
The percentage change in quantity demanded is greater than the percentage change in the influencing variable.
Inelastic response
The percentage change in quantity demanded is smaller than the percentage change in the influencing variable.
Price elasticity of demand (PED)
Price elasticity of demand measures how responsive quantity demanded is to a change in price.
PED formula
PED = % change in quantity demanded ÷ % change in priceFor most products, PED is negative because price and quantity demanded usually move in opposite directions. When classifying demand as elastic or inelastic, focus on the size of the value.
Price inelastic demand
|PED| < 1. Demand changes by a smaller percentage than price. A 10% price rise with PED −0.4 would be associated with an approximate 4% fall in quantity demanded.
Worked example: using PED
Situation: price falls by 8% and quantity demanded rises by 20%.
Calculation: PED = +20% ÷ −8% = −2.5.
Interpretation: demand is price elastic because the absolute value is greater than 1. Sales volume is relatively sensitive to price.
Factors affecting PED
Availability of substitutes
If customers can switch easily to close alternatives, demand tends to be more price elastic. Strong differentiation and brand loyalty can reduce this sensitivity.
Time
Demand may be less price sensitive in the short run because consumers have not yet searched for alternatives. Over time they have more opportunity to switch.
Type of product
Frequently purchased convenience or necessary items may be less price sensitive than products for which customers actively compare alternatives.
Proportion of income
A product taking a large share of income is more likely to attract careful price comparison, making demand more price sensitive.
Brand versus product category
Demand for one brand is often more elastic than demand for the whole product category because customers can switch brands more easily than stop buying the product altogether.
Strength of differentiation
Distinctive features, service, reputation or loyalty can make substitutes seem less comparable and help make demand more price inelastic.
PED, total revenue and profit
If demand is price elastic
A price cut can increase total revenue because the percentage rise in quantity demanded is larger than the percentage fall in price. A price rise tends to reduce revenue.
If demand is price inelastic
A price increase can increase total revenue because sales fall proportionately less than the price rises. A price cut tends to reduce revenue.
Revenue example: 10,000 units at $5 generate $50,000. If price falls to $4 and sales rise to 15,000, revenue becomes $60,000. Revenue rises, but profit is not guaranteed to rise: the business must also consider the additional costs of producing and selling the extra units.
| Demand | Price decreases | Price increases |
|---|---|---|
| Price elastic | Total revenue tends to rise | Total revenue tends to fall |
| Price inelastic | Total revenue tends to fall | Total revenue tends to rise |
Income elasticity of demand (YED)
Income elasticity measures how quantity demanded reacts to a change in consumer income.
YED formula
YED = % change in quantity demanded ÷ % change in income| YED result | Interpretation | Likely business implication |
|---|---|---|
| Positive | Normal product: demand moves in the same direction as income | Demand may rise in an economic expansion and fall in a downturn |
| Negative | Inferior product: demand moves in the opposite direction to income | Demand may increase when incomes fall |
| Greater than +1 | Income elastic; often associated with luxury products | Demand can change strongly when incomes change |
| Between 0 and +1 | Income inelastic; often associated with necessities | Demand changes less than income |
Worked example: YED
Income rises: 10%.
Demand rises: 25%.
YED: 25 ÷ 10 = +2.5.
Meaning: the product is normal and income elastic. If managers expect strong income growth, they may forecast a relatively large increase in demand.
Promotional elasticity of demand
Promotional elasticity measures the responsiveness of quantity demanded to changes in promotional expenditure.
Promotional elasticity formula
Promotional elasticity = % change in quantity demanded ÷ % change in promotional expenditureA larger positive value suggests demand has been relatively responsive to changes in promotional spending.
Worked example: promotional elasticity
Promotion budget: increases from $4m to $5m = 25% increase.
Promotional elasticity: +0.8.
Expected demand change: 0.8 × 25% = 20% increase, assuming other factors are unchanged.
Limitations of elasticity
- Elasticity values are estimates; managers cannot know the exact response until market conditions actually change.
- Markets change continually, so an elasticity calculated from past data may become outdated.
- Other factors may change at the same time, making it difficult to isolate the effect of price, income or promotion.
- Different customer segments may have different elasticities.
- Even a useful elasticity result does not by itself show whether profit will rise because costs also matter.
Evaluation: elasticity is most useful when the estimate is based on relevant, recent data and the market is reasonably stable. In rapidly changing markets, use it alongside market research and judgement rather than treating one coefficient as certain.
Product development
New products can help a business respond to changing tastes, exploit new technology, replace products approaching decline and create growth. However, product development requires investment and many ideas never reach commercial launch.
Research and development (R&D) applies scientific or technical knowledge to create products or improve production processes.
The new product development process
1. Idea generationCreate possibilities and screen for basic feasibility.
2. Concept testingUse research to test whether customers value the idea and which features matter.
3. Business analysisEstimate revenue, costs, investment and likely financial return.
4. Product & process developmentDevelop the product and a practical way of producing it.
5. Test marketingTrial the product with a limited market and observe customer response.
6. LaunchCommercialise the product and support it with production, distribution and marketing.
Ideas may be rejected at any stage. Technical problems, weak demand, excessive cost or an unattractive business case can stop the process. In regulated industries, development may take many years because testing and approval requirements are extensive.
Sources of new-product ideas
Internal discussion and brainstorming
Employees can identify customer problems, production improvements and new uses for existing capabilities.
Research departments
Dedicated R&D teams may discover new technologies, materials, processes or product features.
Customers
Feedback, complaints, surveys, customer-service interactions and communities can reveal unmet needs.
External intellectual property
A business may license patented technology or purchase rights to use another organisation's idea.
Franchising and partnerships
A firm may obtain a proven concept through a franchise or collaborate with another organisation.
Innovative culture
Organisations that encourage experimentation and accept sensible failure are more likely to generate a continuing flow of ideas.
Why businesses invest in R&D
- Create differentiated products and potential competitive advantage.
- Respond to changing consumer needs and technology.
- Develop more efficient production processes and reduce unit costs.
- Build a pipeline of new products to replace ageing or patent-expiring products.
- Generate intellectual property that may itself become a valuable asset or licensing source.
Risks and limitations of R&D
- Research can be expensive and may produce no commercially successful outcome.
- A technically successful product may still fail because of poor positioning, weak promotion or changing tastes.
- Competitors may respond quickly with alternatives.
- Long development periods increase uncertainty because market conditions can change before launch.
- Heavy spending on R&D has an opportunity cost because resources cannot be used elsewhere.
Protecting ideas
| Protection | What it protects | Key point |
|---|---|---|
| Patent | A genuinely new product or process | Can give the owner exclusive rights for a period; in the textbook's UK example this is 20 years after registration. |
| Copyright | Original creative work such as writing, music or artistic work | Protection arises automatically rather than through patent registration. |
| Trademark | Brand identifiers such as names, logos and designs | Helps protect distinctive branding from imitation. |
Protection can create value but enforcement may be costly. A firm operating internationally may also need protection in multiple jurisdictions.
Evaluation: high R&D spending is not automatically better. The appropriate level depends on the industry, speed of technological change, product life cycles, financial resources, competitive intensity and the firm's ability to turn ideas into successful products.
Sales forecasting
A sales forecast estimates the future volume or value of a firm's sales. It is central to planning because expected sales influence revenue, cash flow, capacity, inventory, staffing and investment decisions.
Finance
Forecast sales influence expected profit, cash-flow planning, funding needs and projected return on investment.
Operations
They guide capacity, production schedules, purchases, inventories and distribution plans.
Human resources
Forecast growth may require recruitment, training or redeployment; weaker forecasts may lead to hiring freezes or redundancies.
Marketing
Managers compare actual sales with forecasts and may alter price, promotion, targeting or product strategy when performance differs.
Quantitative forecasting: moving averages
Sales figures often fluctuate from period to period. A moving average smooths short-term highs and lows so that the underlying trend is easier to see. A four-period moving average takes four consecutive observations, calculates their average, then moves forward one period and repeats the calculation.
Worked four-period moving average
Monthly sales ($m): January 5, February 12, March 30, April 15, May 10.
January–April: (5 + 12 + 30 + 15) ÷ 4 = 15.5.
February–May: (12 + 30 + 15 + 10) ÷ 4 = 16.75.
Why centre? An even-numbered moving average falls between periods. Averaging adjacent moving averages places the smoothed value against a specific period.
Centred result: (15.5 + 16.75) ÷ 2 = 16.125.
Extrapolation
Extrapolation projects an identified past trend into the future. It can be useful when market conditions are stable and previous patterns are likely to continue. It is less reliable when technology, competitors, consumer tastes, regulation or the economy change sharply.
Correlation
Correlation identifies an apparent relationship between variables. It can help managers explore which factors move with sales and use expected changes in those factors to inform a forecast.
Two variables tend to move in the same direction. For example, advertising expenditure and sales may both rise.
Variables tend to move in opposite directions. Price and quantity demanded often show this pattern.
Critical point: correlation does not prove causation. If advertising and sales rise together, advertising may have contributed, but sales could also have risen for another reason—or stronger sales may have enabled the business to spend more on advertising.
Market research and test marketing
Primary and secondary research can identify changing trends rather than assuming the future will copy the past. A test market exposes a product to a limited but representative group before a full launch. This can reveal customer reactions and allow changes to be made. However, the sample may not represent the wider market, and competitors may learn about the product and respond before the full launch.
Qualitative sales forecasting
Qualitative forecasting relies more on judgement, experience and expert opinion than on statistical relationships. It is especially useful when the market is changing quickly, the product is new or historical data are weak.
Managerial judgement
Experienced managers or sales staff use their knowledge of customers and the market to form an informed estimate.
Expert opinion
Industry specialists can be consulted when specialist knowledge is more useful than historical trends.
Delphi technique
A group of experts gives views independently. Their responses are summarised and circulated for further rounds until a more settled view or consensus emerges.
Combination approach
Businesses often combine quantitative data with market research and expert judgement rather than rely on one method alone.
Reliability and usefulness of forecasts
Forecasts are more likely to be useful when the data are recent and high quality, market conditions are reasonably stable, test markets are representative, experts understand the market, and the time horizon is relatively short. Long-term forecasts are normally more uncertain because more can change.
Why forecasts help
- Force managers to think ahead.
- Improve co-ordination between marketing, operations, HR and finance.
- Give a basis for budgets, capacity plans and cash-flow forecasts.
- Help managers prepare for different scenarios.
- Can be revised as new information becomes available.
Why forecasts can fail
- Unexpected external shocks can break past patterns.
- Historical relationships may no longer apply.
- Poor samples or biased research can mislead.
- Expert judgement can be affected by optimism or bias.
- Forecasts can create false confidence if treated as certain.
Evaluation: a forecast does not need to be perfectly accurate to be valuable. Knowing whether future demand is likely to be around 2 million or 4 million units can materially change capacity, staffing and finance decisions. The key is to update the forecast as conditions change.
8.1 revision checklist
Questions open in a pop-up. Each answer is marked immediately, with an explanation so you know why it is correct or incorrect.