Elasticity

Price Elasticity of Demand (PED) is one of the most powerful concepts in microeconomics. It measures how sensitive quantity demanded is to a change in price — and the answer determines how firms should price their products and how governments should tax them.

The formula and interpretation

PED = % change in quantity demanded / % change in price.

Because demand and price move in opposite directions (the law of demand), PED is always negative. The negative sign is usually ignored when interpreting; the absolute value is what matters.

Interpreting values

• PED = 0: Perfectly inelastic — quantity demanded unchanged by any price change (vertical demand curve).
• 0 < PED < 1: Inelastic — quantity changes proportionately less than price.
• PED = 1: Unit elastic — price and quantity change by the same percentage.
• PED > 1: Elastic — quantity changes proportionately more than price.
• PED = ∞: Perfectly elastic — any price rise eliminates demand entirely.

Worked example. Price rises 20%, quantity demanded falls 10%. PED = -10/+20 = -0.5. Demand is inelastic.

Factors affecting PED

1. Substitutes. More substitutes → more elastic.
2. Necessity vs luxury. Necessities inelastic; luxuries elastic.
3. Time period. Short-run inelastic; long-run more elastic.
4. Proportion of income. Small share inelastic; large share elastic.
5. Habit/addiction. Addictions are very inelastic.

Importance for firms

The most important application is total revenue analysis:

• Total Revenue = Price × Quantity.
• If demand is INELASTIC: raising prices → revenue rises (price effect dominates).
• If demand is ELASTIC: raising prices → revenue falls (quantity effect dominates).

This explains pricing strategies across industries:

• Luxury brands (Apple, Rolex) have inelastic demand → raise prices to grow revenue.
• Generic products (clothing, basic groceries) have elastic demand → keep prices low; compete on volume.
• Addictive products (cigarettes, alcohol) have very inelastic demand → maintain high prices.

Importance for governments

PED is central to tax policy:

• Tax inelastic goods to raise revenue. Cigarettes, alcohol, petrol — large tax rises bring large revenue with limited demand reduction.
• Don't tax inelastic essentials (food, basic clothing). Tax burden falls heavily on the poor; politically unacceptable.
• Carbon taxes work better long-run than short-run — short-run demand for petrol is very inelastic, but long-run is more elastic as people buy EVs.

Worked tax example. Tobacco. PED of cigarettes typically 0.3-0.5. A 50% tax rise raises retail price 35-40%. Quantity falls by ~15-20%. Government revenue rises sharply. Smoking falls, especially among young people who are more price-sensitive.

Importance for resource allocation

PED helps predict how markets respond to changes:

• Inelastic supply + demand shock → big price changes (agricultural markets after droughts).
• Elastic supply + demand shock → big quantity changes (manufacturing with spare capacity).

Limitations of PED

• Calculated values are approximations. Demand isn't constant — changes over time, income levels, contexts.
• Different over different price ranges. Demand may be elastic at high prices but inelastic at low prices.
• Doesn't capture all consumer behaviour. Status purchases, addictions, irrational behaviour challenge simple PED.

Conclusion. PED is the central tool for understanding how price changes affect demand quantity and revenue. Firms use it to set prices; governments use it to design taxes; both use it to predict market responses to changes. Higher elasticity = greater sensitivity to price; lower elasticity = less responsiveness. The skill is not just calculating PED but APPLYING it to real decisions — which products to tax heavily, which to subsidise, which to price premium, which to price competitively.

The two products have very different elasticities — one inelastic, one elastic. The firm's pricing strategy must reflect this. Getting it wrong on either product costs revenue and competitive position.

Branded sports drink (PED 0.6 — INELASTIC)

The sports drink is INELASTIC (PED < 1). This means:

• A 10% price rise → quantity falls only 6%.
• A 10% price cut → quantity rises only 6%.

Why inelastic?

• Brand loyalty (strong identity, advertising).
• Limited substitutes seen as equivalent (consumers prefer their brand).
• Often bought during/after exercise — when consumers are in 'thirsty, need it now' mode (low price sensitivity).
• May represent small share of income for active consumers.

Pricing strategy: RAISE prices.

Calculation:

• Current price £2, quantity 100,000/month, TR = £200,000.
• Raise price 10% to £2.20. Quantity falls 6% to 94,000. TR = £206,800. Revenue rises £6,800.

Or even more aggressively:

• Raise price 20% to £2.40. Quantity falls 12% to 88,000. TR = £211,200. Revenue rises £11,200.

Higher price strategy:

• Higher margin per unit.
• Higher total revenue.
• Reinforces brand as 'premium' — consistent with marketing.
• Funds further investment in brand-building.

Risk: if price rises too much, demand may eventually become more elastic (consumers do find substitutes, switch brands). Monitor for signs of customer switching.

Budget bottled water (PED 1.8 — ELASTIC)

The bottled water is ELASTIC (PED > 1). This means:

• A 10% price rise → quantity falls 18%.
• A 10% price cut → quantity rises 18%.

Why elastic?

• Many substitutes (tap water, competing budget brands).
• Commoditised product (consumers don't strongly prefer any brand).
• Often bought as a commodity (price the deciding factor).
• May represent significant share of regular shopping for some households.

Pricing strategy: CUT prices to grow revenue.

Calculation:

• Current price £0.50, quantity 200,000/month, TR = £100,000.
• Cut price 10% to £0.45. Quantity rises 18% to 236,000. TR = £106,200. Revenue rises £6,200.

Or even more aggressively:

• Cut price 20% to £0.40. Quantity rises 36% to 272,000. TR = £108,800. Revenue rises £8,800.

Lower price strategy:

• Higher volume.
• Higher total revenue.
• Competitive position improves vs other budget brands.
• Economies of scale on higher volume.

Risk: lower price reduces margin per unit. The firm must ensure variable costs don't exceed the lower price. Also, may train customers to expect low prices and reduce future pricing power.

Strategic implications

The two products require OPPOSITE pricing strategies:

• Sports drink: premium pricing strategy.
• Bottled water: competitive/discount pricing strategy.

This means the firm needs:

• Different marketing approaches — premium positioning for sports drink; value positioning for water.
• Different distribution — sports drink in premium retail; water in mass-market discount.
• Different brand identities — separate brands to avoid confusion.

Could the firm shift the elasticities?

• Reduce elasticity of bottled water through branding, marketing, exclusive variants. Convert it from commodity to premium → enables higher prices.
• Increase elasticity of sports drink through new competitors entering. Forces price competition.

But fundamentally:

• Sports drink elasticity reflects loyalty/identity factors → likely durable advantage.
• Water elasticity reflects commoditisation → hard to escape without major investment.

Conclusion. The firm should pursue opposite pricing strategies for its two products — raise prices on the inelastic sports drink to grow revenue; cut prices on the elastic bottled water to grow volume and revenue. The strategy reflects the underlying elasticity, which reflects the brand power and substitutability. Getting this wrong (cutting sports drink prices or raising water prices) would reduce revenue. The two products need different strategies, different marketing, and possibly different brand identities — even though they're in similar physical categories.

The deeper insight is that elasticity is the SINGLE MOST IMPORTANT PIECE OF INFORMATION for pricing decisions. Firms that know their PED price optimally; firms that don't price by intuition and often get it wrong. Sophisticated firms (Coca-Cola, Apple, Amazon) measure elasticity continuously through pricing experiments — adjusting prices to find the revenue-maximising point.

Heavy tobacco taxes are one of the most studied public health and revenue policies. The economic analysis is rich — combining elasticity, externalities, revenue raising, distributional effects, and unintended consequences. The right answer requires weighing multiple objectives.

Why taxes work for cigarettes

PED for cigarettes is typically 0.3-0.5 — very inelastic. This is because:

• Addiction (chemical dependence makes quitting hard).
• No close substitutes (nicotine patches and gum are weak replacements).
• Strong habit/identity component.
• Often consumed despite knowing health risks.

This inelasticity means:

• Tax raises revenue. A 50% tax rise raises retail price ~35-40%; quantity falls only 15-20%. Tax revenue rises substantially.
• Quantity does fall. Tax does reduce smoking, particularly among young people (more price-sensitive) and lower-income smokers (larger share of income).

Objective 1: Raising government revenue

Tobacco taxes are a major revenue source — typically £10-15bn/year in UK, £30-50bn in US. Used to fund healthcare, public services.

Effect: Revenue rises with each tax increase up to a point (eventually demand becomes more elastic at very high prices).

Verdict: Highly effective revenue raiser.

Objective 2: Reducing smoking rates and health damage

Tobacco kills around 50% of long-term users (estimated 8 million deaths globally per year). Heavy taxes reduce smoking, particularly:

• Initiation among young people (highest PED among smokers).
• Quitting among existing smokers (some).
• Reducing intensity (cutting down).

Effect: Smoking rates have fallen in most countries with heavy taxes — UK from 25%+ in 1990s to 14% today.

Verdict: Effective in reducing smoking gradually.

Objective 3: Reducing healthcare costs

Smoking-related illness costs healthcare systems billions annually (lung cancer, COPD, heart disease).

Effect: Reduced smoking → reduced future healthcare costs → fiscal saving.

Verdict: Long-term benefit but takes 20-30 years to materialise.

Objective 4: Reducing externalities

Smoking imposes costs on others — passive smoking, healthcare burden borne by all taxpayers.

Effect: Tax forces smokers to internalise some of this external cost (polluter-pays principle).

Verdict: Economically efficient — corrects market failure.

Downsides and unintended consequences

1. Regressive nature.

• Smokers tend to be lower-income.
• A flat-rate tax takes a higher share of poor smokers' income.
• Worsens income inequality.

2. Black market.

• Heavy taxes → smuggling, counterfeit cigarettes, illegal sales.
• UK loses estimated £2-3bn/year to illegal tobacco trade.
• Black market cigarettes often more dangerous (untested, unregulated).

3. Cross-border shopping.

• High-tax countries lose revenue to neighbours with lower taxes.
• EU experiences cross-border shopping for cigarettes.

4. Disproportionate effect on poor.

• Some poor smokers cut food/heating spending rather than quit.
• 'Quitting' is harder for those with limited resources for nicotine replacement therapy.

5. Doesn't address other addictions.

• Tax tobacco; people may switch to vapes/e-cigarettes (lower health risks but different challenges).
• May not deter heavy smokers (most committed users least price-sensitive).

6. Equity questions.

• Is it fair to tax an addictive substance heavily when addicts can't easily stop?
• Should government use addiction for revenue?

Optimal tax level

Economists debate optimal tobacco tax:

• TOO LOW: doesn't deter smoking or raise much revenue.
• TOO HIGH: creates large black market; doesn't reduce smoking proportionately.
• 'Sweet spot' typically considered to be tax at 70-80% of retail price.

Comparing with alternative interventions

Tobacco taxes work alongside:

• Public health campaigns (warnings, education).
• Restrictions on advertising and sales (no smoking in public places).
• Nicotine replacement therapy availability.
• Education in schools.
• Plain packaging laws.

A COMPREHENSIVE approach — taxes PLUS regulation PLUS public health PLUS supportive interventions — is more effective than taxes alone.

Justified judgement

Heavy tobacco taxes are broadly the right policy — they raise significant revenue, reduce smoking and health damage, internalise externalities, and can be designed to be effective. But they should:

1. Be set at the optimal level (~70-80% of price) — not so high they create black markets.
2. Be accompanied by support for smokers wanting to quit (nicotine replacement, mental health, addiction services).
3. Be combined with regulation and public health — not relied on alone.
4. Be progressively designed — perhaps with rebates for low-income smokers wanting to quit.
5. Be coordinated internationally to reduce cross-border evasion.

Conclusion. Heavy tobacco taxes deliver substantial benefits — revenue, reduced smoking, lower healthcare costs, externality correction. They work BECAUSE demand is inelastic in the short run; they're moderately effective in reducing smoking long-term. But they create unintended consequences (regressive nature, black market) that need management. The right policy is heavy taxation as part of a broader strategy, not as a sole instrument. The mistake to avoid is treating taxes as the complete solution; they're an essential tool within a comprehensive approach to tobacco control.

The deeper insight is that elasticity determines policy effectiveness. Heavy taxes work for tobacco BECAUSE demand is inelastic — most consumers can't or won't quit despite price rises. If demand were highly elastic (many substitutes; non-addictive), heavy taxes would simply destroy the market without raising much revenue. Understanding the underlying behaviour is essential to designing effective economic policy.

Different YEDs mean different impacts of recession on different firms. The strategic responses must be carefully tailored. This question tests whether students can apply income elasticity dynamically to business strategy.

Calculate the impact

Firm A (designer handbags, YED = +3)

• Income falls 5%.
• Demand changes by YED × % income change = +3 × −5% = −15%.
• Sales fall 15%. Major revenue hit.

Firm B (budget supermarket food, YED = −0.5)

• Income falls 5%.
• Demand changes by −0.5 × −5% = +2.5%.
• Sales RISE 2.5% — counter-intuitive but logical (people trade DOWN to budget brands in recession).

The same recession affects the two firms in OPPOSITE directions.

Firm A — Strategic responses to falling demand

Option 1: Maintain prices, accept volume drop.

• Brand integrity preserved.
• 15% volume drop is manageable for a luxury brand with high margins.
• Recession-proof customer base (top 10% incomes) less affected.

Option 2: Selective discounting.

• Sales on outlet/older lines preserves brand at full price for new collections.
• Captures some volume without permanent price reduction.

Option 3: Down-market extension.

• Launch sub-brand at lower price points (e.g. 'Brand X Diffusion').
• Captures customers trading down BUT risks diluting main brand.
• Coach, Marc by Marc Jacobs are examples of luxury houses extending downward.

Option 4: Reduce costs / smaller workforce.

• Cut variable costs (raw materials, marketing) in proportion to sales drop.
• Layoffs of non-essential roles.
• Painful but necessary if recession deepens.

Option 5: International expansion.

• Markets less affected by recession (Asian markets, growing emerging economies) may offset Western recession.
• Long-term strategic move.

Option 6: Investment in brand-building.

• Counter-intuitive but: rivals retreat in recession; this firm could gain share by investing more in marketing.
• Many top brands made share gains in past recessions through brand investment.

Recommended for Firm A: Combination of Options 1 + 3 + 6 — maintain premium positioning AND launch diffusion line AND invest in brand-building. Accept short-term margin pressure for long-term position.

Firm B — Strategic responses to rising demand

Option 1: Expand capacity to meet demand.

• Open new stores in strategic locations.
• Increase product range (more SKUs to capture trade-down customers).
• Hire more staff.

Option 2: Maintain low prices to lock in new customers.

• Don't raise prices despite higher demand.
• Convert recession-driven trial into long-term loyalty.

Option 3: Marketing message tailored to recession.

• 'Smart shopping', 'value for money' messaging.
• Position as 'sensible choice' rather than 'second-best'.

Option 4: Improve product quality where possible.

• Some trade-down customers will return to premium when recession ends.
• Keeping quality high reduces this churn.

Option 5: Geographic expansion.

• Recession increases addressable market (more customers willing to trade down).
• Expand into areas previously dominated by premium retailers.

Option 6: Investment in efficiency.

• Use higher sales volumes to drive economies of scale.
• Build long-term cost advantage.

Recommended for Firm B: Combination of Options 1 + 3 + 5 — expand capacity, market the value message, expand geographically. Don't raise prices despite demand rise — lock in customers.

Cross-cutting strategic considerations

For both firms:

1. Cash management. Recession reduces consumer confidence; cash flow may be unpredictable. Both firms should preserve cash, manage receivables tightly.

2. Customer relationships. Both firms should INVEST in customer experience — A to retain premium customers; B to convert recession trials into loyal customers.

3. Long-term thinking. Recessions end; firms that survived and gained share have advantage. Both should think 18-36 months ahead.

4. Competitor watch. Some competitors will fail in recession. Both firms should be ready to acquire failed rivals' assets cheaply (locations, talent, customer lists).

The YED insight

The two firms have opposite responses to recession because:

• High YED (luxury) products contract in recession.
• Negative YED (inferior) products expand in recession.

Recession is good for SOME firms (budget grocers, discount retailers, value brands, debt collection agencies, repair services, second-hand goods). Recession is bad for OTHERS (luxury brands, big-ticket items, premium dining, holidays).

This is economic cycle awareness — sophisticated firms know where they sit on the YED spectrum and prepare for both expansions and contractions.

Wider impacts of the recession

• Long-term: when recession ends, Firm A's customers may not all return (some permanently traded down); Firm B's new customers may not all stay (some trade back up).
• Behavioural change: recessions sometimes permanently shift consumer habits (e.g. people who started cooking at home during recessions often continue).
• Industry restructuring: weaker firms in both segments fail; survivors gain share. Recession accelerates structural change.

Justified judgement

Firm A (luxury, high positive YED) should defend its premium position while extending strategically downward. Firm B (inferior, negative YED) should capture the trade-down opportunity by expanding capacity, marketing, and geography. Both should manage cash carefully, invest in customer relationships, and think long-term.

Conclusion. The same recession affects different firms in opposite directions depending on their YED. Firm A (luxury, YED +3) faces a 15% sales fall and must defend premium position while extending strategically. Firm B (inferior, YED -0.5) experiences a 2.5% sales rise and should capture the trade-down opportunity. Both firms must manage cash, invest in customer relationships, and think long-term. The deeper insight is that recessions create both losers AND winners — firms that understand their YED position can prepare accordingly.

The strategic insight is that elasticity is a DYNAMIC concept. YED determines how firms experience the business cycle. Some firms are counter-cyclical (discount retailers, debt collection); some are highly pro-cyclical (luxury). Smart firms know their position and plan for both upswings and downswings. The 2008 recession, 2020 pandemic, and 2022 inflation all reshaped industries because YED determined who won and lost. Firms that survive recessions often do so by knowing what their YED implies and responding strategically — not by hoping the recession won't affect them.