Elasticity

Marketing · 3 min read

Elasticity is the measure of how much customers change their behaviour when prices change. Some products are tightly tied to the price tag. Others barely notice. Knowing which one you sell is the difference between thoughtful pricing and gambling.

Raise the price of gasoline by 10%. People grumble, but most of them keep buying roughly the same amount. They still have to get to work. They still have to drive the kids to school. Raise the price of restaurant steak by 10%. A significant portion of customers switch to chicken, or to pasta, or to staying home. Same percentage increase, dramatically different customer response.

The reason has a name. Economists call it price elasticity of demand — and it is one of the most consequential concepts in pricing, marketing, and business strategy. Most people who run businesses make pricing decisions without ever knowing whether their product is elastic or inelastic. The same percentage price change can make a business or destroy it, depending entirely on which side of the elasticity line they happen to sit on.

Price elasticity of demand measures how much the quantity demanded changes when the price changes. The technical formula divides the percentage change in quantity demanded by the percentage change in price. If a 10% price increase causes a 20% drop in sales, the elasticity is 2.0 — quantity moved twice as much as price. If the same 10% increase causes only a 2% drop in sales, the elasticity is 0.2 — quantity barely moved. The numbers feel abstract, but the implications are not.

Products are usually grouped into three categories based on how their demand responds.

Elastic demand describes products where customers are highly sensitive to price changes. A small price increase produces a much larger drop in sales. Most luxury goods, restaurant meals, vacations, entertainment, and discretionary purchases fall into this category. Customers have alternatives — they can buy less, switch brands, postpone the purchase, or skip it entirely. Raising prices on elastic products usually reduces total revenue, because the sales loss outweighs the higher price per unit.

Inelastic demand describes products where customers keep buying nearly the same amount even when prices change significantly. Essential medications, gasoline, utilities, addictive products, and goods without substitutes fall here. Customers have few alternatives, so they absorb the price increase rather than reduce consumption. Raising prices on inelastic products usually increases total revenue, because the lost sales are small relative to the gain per unit. This is why utilities and pharmaceutical companies can sustain pricing power that other industries cannot.

Unit elastic demand describes the rare middle case where percentage changes in price and quantity exactly cancel out. A 10% price increase produces a 10% drop in sales, leaving total revenue unchanged. This is less a category that products fall into and more a theoretical line that separates the two real categories.

The factors that determine elasticity are predictable. Products tend to be more elastic when substitutes are readily available, when the purchase is discretionary rather than essential, when the cost represents a significant portion of the buyer's income, when customers have time to find alternatives, and when the product is well known and easily compared. Products tend to be more inelastic when substitutes are scarce, when the purchase is necessary, when the cost is small relative to income, when customers are buying urgently, and when the product is differentiated in ways that make comparison difficult.

Strategically, elasticity is the hidden engine behind almost every pricing decision. A grocery store can run a 20% promotion on Coca-Cola and watch volume spike because cola is elastic — customers stock up. The same grocery store cannot run a 20% promotion on insulin and expect a similar response, because insulin is profoundly inelastic — patients who need it were going to buy it anyway. Airlines run elaborate dynamic pricing systems precisely because the elasticity of a business traveler booking a Tuesday flight is dramatically different from the elasticity of a family planning a summer vacation six months out. The same seat on the same plane gets sold to different customers at different prices because the elasticity of each customer's demand is different.

For any business considering a price change, the most important question is not how much should we change it. It is how elastic is our demand. A 5% price increase on a highly elastic product can shrink revenue noticeably. A 5% price increase on an inelastic product can grow revenue substantially with little customer loss. Same decision, opposite outcomes.

The most useful frame for understanding elasticity is this: elasticity tells you how much pricing power you have. Inelastic products have pricing power — customers will absorb the change because they have nowhere else to go. Elastic products do not — customers will leave the moment the price feels wrong. Most pricing mistakes come from misjudging which kind of product you actually sell.