The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →A shift in the demand curve means buyers want a different quantity of a good at every price because something other than that good’s own price has changed. More demand shifts the curve right; less demand shifts it left. A change in the good’s own price instead moves buyers along the existing curve.
What a demand curve shows
A demand curve represents the relationship between a good’s price and the quantity buyers are willing to purchase, assuming other relevant conditions stay constant. The whole curve describes demand; a particular point on it shows the quantity demanded at one price.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
Principles of Economics | $270.79 | Buy on Amazon |
| 2 |
|
Basic Economics: A Common Sense Guide to the Economy | $25.49 | Buy on Amazon |
| 3 |
|
Economics For Dummies: Book + Chapter Quizzes Online | $17.49 | Buy on Amazon |
| 4 |
|
Principles of Economics | $177.99 | Buy on Amazon |
| 5 |
|
Understanding Economics, Student Edition (ECONOMICS PRINCIPLES & PRACTIC) | $46.61 | Buy on Amazon |
When a non-price factor changes that relationship, the curve shifts: at any given price, buyers now want a different quantity than before. A shift to the right represents increased demand at each price, while a shift to the left represents decreased demand at each price. OpenStax’s explanation of demand shifts uses this distinction.
Shift in demand vs. movement along the curve
| What changes | What happens | How to describe it |
|---|---|---|
| The good’s own price | Buyers choose a different quantity at the new price, represented by another point on the same curve. | A change in quantity demanded; movement along the demand curve. |
| A non-price determinant, such as income or preferences | The quantity buyers want differs at each price, represented by a new curve. | A change in demand; the curve shifts. |
As OpenStax puts it, “A change in the price of a good or service causes a movement along a specific demand curve, and it typically leads to some change in the quantity demanded, but it does not shift the demand curve.” The textbook’s section on shifts in demand and supply explains the distinction. NCERT also separates shifts from movements along a demand curve in its Introductory Microeconomics textbook.
#1 Best Overall
What can shift demand?
Several non-price factors can change how much buyers want at each price. The direction depends on the good and the change being considered; in each example below, other factors are assumed unchanged.
Income
For a normal good, an increase in income tends to raise demand, shifting the curve right; a fall in income tends to reduce it. For an inferior good, the effect can be the opposite: higher income can reduce demand. Whether a good is normal or inferior depends on how consumers respond to income changes.
Rank #2
Preferences
A change in tastes or preferences can raise or lower demand. For example, if consumers become more interested in a product, they may want more of it at each price, shifting demand right.
Number of buyers
If the number of buyers in a market increases, market demand can rise; if the number falls, market demand can decline. This concerns the combined demand of buyers in the market, not just the choices of one consumer.
Rank #3
Expectations
What buyers expect about the future can affect what they choose to buy now. For instance, expectations of a future price increase may lead some buyers to purchase more today, raising current demand.
Prices of related goods
- Substitutes: If a substitute becomes more expensive, buyers may switch toward the good in question, increasing its demand and shifting its curve right.
- Complements: If a good commonly used together with the product becomes more expensive, buyers may want less of the product, reducing its demand and shifting its curve left.
What happens to market price and quantity?
If supply stays unchanged, a demand shift changes the intersection of the demand and supply curves. In the standard model with an upward-sloping supply curve, a rightward demand shift leads to a higher equilibrium price and quantity; a leftward shift leads to a lower equilibrium price and quantity.
Rank #4
Those outcomes rely on the fixed-supply assumption. If supply changes at the same time, the market’s new equilibrium depends on both shifts; the demand shift alone does not determine the final price or quantity.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
