Economics
Price Elasticity of Demand
Quick fact
Salt is one of the most inelastic goods—even a large price hike barely changes how much people buy, because it's cheap, essential, and has no close substitutes.
Why this is interesting
Why does a 10% price increase sometimes make people barely flinch (like for insulin), yet cause a huge drop in sales for other products (like soda)? The answer lies in a simple but powerful economic measure.
Read the full explanation
Understanding Price Elasticity of Demand
Imagine you're at a store and the price of your favorite brand of coffee jumps by 20%. Would you switch to a cheaper brand or buy less? If yes, your demand is elastic—you respond to price. If you keep buying the same amount regardless (like a life-saving medication), your demand is inelastic. Economists calculate elasticity as the percentage change in quantity demanded divided by the percentage change in price. A result greater than 1 means elastic (consumers are sensitive), less than 1 means inelastic (consumers are not very sensitive), and exactly 1 means unitary elasticity—revenue stays the same when price changes.
A deeper explanation
Price elasticity of demand stems from consumer choice and the availability of alternatives. The more substitutes a good has, the more elastic its demand—because consumers can easily switch. Necessities (like food staples or fuel) tend to be inelastic because people need them despite price increases. Luxury goods are typically elastic. Over time, demand becomes more elastic as consumers find alternatives. This concept is crucial for businesses: if demand is elastic, lowering prices can increase total revenue; if inelastic, raising prices boosts revenue. Governments also use it to predict the impact of taxes—excise taxes on inelastic goods (like cigarettes) effectively raise revenue without drastically reducing consumption.