Price Elasticity of Demand: Formula and 5 Examples

Last updated: April 2026

What is price elasticity of demand?

Price elasticity of demand is a single number that answers the question every business, government and central bank cares about: if I move the price by X percent, how much does demand change? A 10% price hike that shrinks sales by 25% behaves very differently from a 10% hike that barely moves the needle. PED captures that ratio in a way that is comparable across goods, markets and time periods.

The concept was formalised by Alfred Marshall in Principles of Economics (1890) and remains a cornerstone of microeconomic analysis. Modern uses range from setting fares at airlines, to designing carbon taxes at the European Commission, to estimating which retail equities have durable pricing power — a question I treat as foundational when screening stocks for CFD positions on Plus500.

Price elasticity of demand formula

The calculation is simple: divide the percentage change in quantity demanded by the percentage change in price.

The result is normally negative or zero, because raising prices reduces quantity demanded — the law of demand. In practice economists usually report the absolute value |PED| and drop the minus sign. When two goods are compared, the one with the larger |PED| is more sensitive to price.

Worked example: cinema tickets

A cinema raises its ticket from $10 to $12 (+20%). Weekly attendance falls from 1,000 tickets to 850 (−15%).

PED = (−15%) ÷ (+20%) = −0.75

Absolute value |PED| = 0.75 — demand is inelastic. Revenue rises from $10,000 to $10,200 despite the lower volume, because the price increase outweighs the lost customers. That asymmetry is the entire point of elasticity analysis: it tells you whether a price move makes you richer or poorer.

How do you interpret a PED value?

The absolute value |PED| sorts goods into five regimes:

What determines price elasticity of demand?

Four factors decide whether demand for a good is elastic or inelastic.

1. Availability of substitutes

The more replacements a good has, the higher its elasticity. Butter is more elastic than salt — you can swap butter for margarine, olive oil or coconut oil; you cannot swap salt for anything. A 30% price rise on butter can cut purchases by 40% or more. The same rise on table salt typically moves demand by 2–3% at most.

2. Share of budget

Goods that consume a large share of a household’s budget are more elastic. A 20% rise in housing costs is alarming — it represents real money. A 20% rise in match prices passes unnoticed because the absolute amount is trivial.

3. Necessity vs discretionary

Necessities (food staples, prescription drugs, energy) have low elasticity because consumers buy them regardless of price. Discretionary goods (vacations, premium electronics, dining out) are highly elastic because consumers can simply postpone or skip the purchase.

4. Time horizon

In the short run, demand is almost always more inelastic. When electricity prices spike, you cannot replace your dishwasher overnight. Over years, you can. The International Energy Agency’s 2024 review estimated short-run residential electricity PED at roughly 0.1–0.2 across OECD economies, but long-run PED — measured over 5–10 years — at 0.4–0.7. The same household becomes about three times more price-sensitive once it has time to adapt.

5 practical examples of price elasticity of demand

1. Gasoline (|PED| ≈ 0.1–0.3)

The textbook case of inelastic demand. When European pump prices jumped roughly 40% during the 2022 energy crisis — from around €1.45/litre to over €2.00/litre in Germany — total fuel consumption fell only about 5–8% across the EU according to Eurostat data. Most drivers had no immediate substitute: they still had to commute, deliver goods and run businesses. The same effect appeared in the US, where the Energy Information Administration reported average daily gasoline consumption falling under 10% despite retail prices peaking above $5/gallon in June 2022.

2. Premium smartphones (|PED| ≈ 1.5–2.5)

High elasticity driven by genuine substitutes. A 20% iPhone price rise pushes a meaningful share of buyers to lower Apple tiers (iPhone SE), to flagship Android alternatives (Samsung Galaxy S, Google Pixel) or to delaying the upgrade by 6–12 months. Apple’s own pricing data shows that each new flagship typically loses 15–25% of unit volume in markets where the price rises more than 10% in local currency, which is why Apple absorbs FX swings in some markets rather than fully passing them through.

3. Airline tickets (|PED| ≈ 1.5–2.0)

Airlines have built an entire discipline — revenue management — around elasticity. Business routes between hub cities show low elasticity for last-minute corporate travel and high elasticity for leisure bookings made weeks ahead. The IATA’s annual price tracker showed that a 30% summer 2023 price rise on intra-European leisure routes cut bookings by roughly 18%, while business-class fares on transatlantic corridors absorbed similar increases with sub-5% volume losses. Same product, different segments, different elasticities.

4. Insulin (|PED| ≈ 0.0–0.1)

Near-perfect inelasticity. Type-1 diabetics need insulin to live; price has almost no effect on physical demand. This is exactly why the United States passed the Inflation Reduction Act of 2022, which capped Medicare insulin out-of-pocket costs at $35 per month starting in 2023. Without regulation, the inelastic curve is what allowed list prices for popular insulins like Humalog and Lantus to rise more than 600% between 2001 and 2017 with virtually no demand response. Inelastic markets without competitive substitutes are the canonical case for price regulation.

5. Restaurants and dining out (|PED| ≈ 1.8–2.5)

Highly elastic because there is a perfect home substitute: cooking. The 2022–2024 inflation cycle in the EU and US showed this at scale. UK Office for National Statistics data recorded restaurant and café prices rising 10–13% year over year in 2023, but real visits per capita fell over 12% across the same period as households shifted spending to grocery purchases. The pass-through stopped working: restaurants raised prices, lost customers, and saw flat or declining real revenue.

Why does price elasticity of demand matter in practice?

Corporate pricing strategy and equity selection

A company with inelastic demand has pricing power — it can raise prices to defend margins when input costs rise. A company with elastic demand cannot, because customers leave. This is the lens Warren Buffett uses when describing economic moats, and it is the single most important screen I run before opening a long CFD position. Consumer staples (Procter & Gamble, Coca-Cola), pharmaceuticals with on-patent drugs, and utility-style infrastructure firms historically show inelastic demand. Discretionary retail, airlines and most consumer electronics do not. During the 2022 cost shock, S&P 500 companies in the top quintile of pricing power expanded gross margins by an average of 80 basis points; the bottom quintile contracted by more than 200 basis points, according to Goldman Sachs equity research.

Excise taxes and fiscal policy

Governments deliberately tax inelastic goods. Tobacco, alcohol and fuel duties generate stable revenue precisely because consumers do not stop buying when prices rise. The UK Soft Drinks Industry Levy (the “sugar tax”) of 2018 was an exception designed to change behaviour — and it worked partially because the levy was structured to push manufacturers to reformulate, not because consumer demand was very elastic. The EU’s 2022 windfall tax on energy producers (Council Regulation 2022/1854) was justified on similar elasticity logic: prices stayed high, demand stayed inelastic, and the resulting profits were taxed without significant distortion.

Market regulation

Elasticity is the implicit argument behind most price regulation. Life-saving medicines have inelastic demand, so unregulated monopolists can charge extreme prices; this is why the EU’s pharmaceutical pricing regimes (HTA Regulation 2021/2282) and the US Medicare drug price negotiation provisions (Inflation Reduction Act 2022) explicitly reference market power and limited substitution. When demand is elastic, regulation is rarely needed because consumers discipline sellers themselves.

Price elasticity of demand in the age of AI

This is where most existing English-language coverage stops short. Two recent shifts deserve attention.

AI-driven dynamic pricing is amplifying elasticity exploitation

Large retailers, ride-sharing platforms and travel sites now use machine-learning models to estimate elasticity at the level of an individual transaction — sometimes an individual user. Uber’s surge pricing and Amazon’s algorithmic price changes (which can adjust millions of SKU prices per day) are mainstream examples. The economic mechanism is straightforward: if the system can identify the segment of inelastic buyers (commuters in a rainstorm, last-minute shoppers, gift purchasers), it can charge them more without losing volume from elastic segments. The European Commission’s 2024 report on personalised pricing flagged this as a fairness concern, and Article 5 of the EU AI Act (in force 2 February 2025) prohibits AI systems that exploit specific vulnerabilities — a category that may extend to algorithmic price discrimination against vulnerable consumers.

Large language models can reason about elasticity — but inconsistently

A growing body of research tests whether LLMs can act as economic agents. John J. Horton’s NBER working paper Large Language Models as Simulated Economic Agents (NBER WP 31122, 2023) showed that GPT-3.5 and GPT-4 reproduce textbook responses to price changes in survey-style experiments. Subsequent work in 2024 — including Brand, Israeli & Ngwe (HBS Working Paper 23-062) and several arXiv preprints — used LLMs to estimate price elasticity directly from product descriptions and consumer reviews, with predictive accuracy approaching that of traditional conjoint analysis at a fraction of the cost. The catch: the same models can be inconsistent across runs, and reasoning-mode prompts often produce different elasticities than zero-shot prompts. For practitioners, this means LLM-derived elasticity estimates are useful as a fast first pass, not a substitute for actual market experiments.

Summary

Price elasticity of demand is the single number that decides whether raising prices helps or hurts revenue, whether a tax raises money or destroys a market, and whether a company has the pricing power to survive an inflation cycle. |PED| below 1 means inelastic demand (gasoline, insulin, electricity); above 1 means elastic (smartphones, flights, restaurants). Four determinants — substitutes, budget share, necessity, and time horizon — explain almost all the variation across goods. Modern AI dynamic pricing is making elasticity estimation cheaper and more granular than at any point in economic history, while regulators are starting to push back on the most aggressive forms of personalised pricing. Understanding PED is the foundation, without which any analysis of consumer behaviour or corporate pricing strategy stays superficial.

For the Polish-language version of this article — including local PL regulatory context (UOKiK, KNF, GUS data on Polish gasoline elasticity during 2022) — see elastyczność cenowa popytu.