Unit elastic describes an elasticity coefficient of exactly 1, meaning the percentage change in quantity demanded or supplied equals the percentage change in price, so a price change leaves total revenue (or total expenditure) unchanged.
Unit elastic is the dividing line in elasticity. When the percentage change in quantity is exactly equal to the percentage change in price, the elasticity coefficient comes out to exactly 1. A 10% price increase paired with a 10% drop in quantity demanded? Unit elastic. A 5% price increase that calls forth exactly 5% more quantity supplied? Also unit elastic.
The CED treats a magnitude of 1 as the benchmark that separates elastic from inelastic. Greater than 1 means elastic (quantity is very responsive to price). Less than 1 means inelastic (quantity barely budges). Exactly 1 means the two changes are perfectly proportional. For demand, this has a famous consequence. The price increase and the quantity decrease cancel each other out, so total revenue doesn't move at all. You're sitting at the peak of the total revenue curve.
Unit elastic lives in Unit 2: Supply and Demand, anchored in Topic 2.4 (Price Elasticity of Supply) and learning objectives 2.4.A, 2.4.B, and 2.4.C. You need to do three things with it. Define it (coefficient = 1, proportional changes), explain its effect on total revenue or total expenditure using graphs, and calculate it from a table or graph of price-quantity data. The total revenue connection is the part the exam loves most. Elastic demand means a price cut raises revenue, inelastic demand means a price cut lowers revenue, and unit elastic is the tipping point where revenue is maximized and a small price change does nothing to it. That single benchmark organizes the entire elasticity chapter, and it comes back in Unit 4 when monopolies pick prices.
Total Revenue (Unit 2)
Unit elastic is where total revenue peaks. On a linear demand curve, the top half is elastic, the bottom half is inelastic, and the exact midpoint is unit elastic. If you can find that point, you've found maximum revenue.
Elastic Demand and Inelastic Demand (Unit 2)
Unit elastic is the fence between these two. A coefficient above 1 is elastic, below 1 is inelastic, and exactly 1 is unit elastic. Classifying a coefficient against this benchmark is one of the most common elasticity MCQs.
Monopoly (Unit 4)
A monopolist never knowingly produces in the inelastic region of its demand curve. Marginal revenue equals zero exactly at the unit elastic point, which is why the revenue-maximizing quantity sits right where demand is unit elastic. This is a classic Unit 2 to Unit 4 link.
Short-run (Unit 2)
Time horizon shapes elasticity of supply. In the short run, firms can't easily adjust production, so supply tends toward inelastic. Given more time, supply becomes more elastic. Unit elastic can show up as the transitional case in between.
Unit elastic shows up most often in multiple choice, and the questions come in two flavors. The first is a classification question. You're given a coefficient (say, 0.75) or a description (quantity supplied changes 'exactly proportionally' to price) and asked to label it as elastic, inelastic, or unit elastic. Memorize the benchmark of 1 and these become free points. The second flavor ties elasticity to total revenue or total expenditure, where you have to recognize that at unit elastic, a price change leaves revenue unchanged. On FRQs, elasticity reasoning is embedded in larger market scenarios. The 2022 exam built a question around individual buyers' willingness to pay in a market for Good X, and elasticity logic is what connects price changes to total expenditure in setups like that. Be ready to calculate elasticity from a table (percentage change in quantity divided by percentage change in price) and then state the total revenue implication, since LO 2.4.B and 2.4.C ask you to explain and calculate, not just define.
These sound similar but are nothing alike. Unit elastic means the coefficient equals exactly 1, with price and quantity changing in equal percentages. Perfectly elastic means the coefficient is infinite, drawn as a horizontal curve, where any price change above or below the going price sends quantity to zero or unlimited. If a question says 'proportional,' that's unit elastic. If it says 'horizontal curve' or 'infinitely responsive,' that's perfectly elastic.
Unit elastic means the elasticity coefficient equals exactly 1, because the percentage change in quantity equals the percentage change in price.
A magnitude of 1 is the benchmark in the CED that separates elastic (greater than 1) from inelastic (less than 1).
When demand is unit elastic, a price change leaves total revenue unchanged, because the price effect and quantity effect cancel out exactly.
On a linear demand curve, the unit elastic point sits at the midpoint, which is also where total revenue is maximized.
The same coefficient formula applies to supply, where unit elastic supply means quantity supplied changes in exact proportion to price.
In Unit 4, a monopolist's marginal revenue hits zero at the unit elastic point of demand, so monopolies never operate in the inelastic range.
Unit elastic means the elasticity coefficient equals exactly 1, so the percentage change in quantity demanded or supplied is exactly equal to the percentage change in price. It's the benchmark separating elastic from inelastic in Topic 2.4.
No. At unit elastic demand, the price change and quantity change are perfectly proportional, so they cancel out and total revenue stays exactly the same. This is also where total revenue is at its maximum.
No, 0.75 is inelastic because it's less than 1. Unit elastic requires the coefficient to equal exactly 1, not approximately 1. This exact classification shows up regularly in multiple choice questions.
Unit elastic has a coefficient of exactly 1, with proportional changes in price and quantity. Perfectly elastic has an infinite coefficient and is drawn as a horizontal curve, where consumers buy any amount at one price and nothing at a higher price.
On a straight-line demand curve, it's the exact midpoint. Above the midpoint demand is elastic, below it demand is inelastic, and total revenue peaks right at the unit elastic midpoint.
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