From NCERTAsked by Anonymous from Dallas, United States24 Oct 2026, 9:59 AM ISTUpdated
In one line
Yes, demand can stay the same even if income changes, for some special goods.
The rule
For some goods, a change in income does not affect the quantity demanded. These are called income-inelastic goods or necessities.
Let's understand it simply
Imagine you buy 1 kg of salt every month for your home. Now, suppose your father gets a salary raise. Will your family start buying 5 kg of salt every month? No! You still need only 1 kg. Even if your income goes up or down, the amount of salt you buy remains the same.
Some goods are like this. No matter how much money you have, you do not buy much more or less of them. These are usually things you really need, like salt, matchboxes, or basic medicines.
How demand changes with income for different goods
Good
If income increases
If income decreases
Salt
No change
No change
Mobile phone
May increase
May decrease
Luxury car
Increases a lot
Decreases a lot
How it works
Income changes: Your income increases or decreases.
Check the good: Is it a basic necessity (like salt or soap)?
Quantity stays same: You still buy the same amount, because you cannot use much more or less.
Demand is unchanged: So, demand does not change with income for these goods.
The story behind it
Economists noticed that for some goods, people’s buying habits don’t change much with income. These goods are called necessities. The idea helps us understand which products people will always need, no matter how rich or poor they are.
Where you see it in real life
Salt for cooking: Families buy about the same amount, no matter their income.
Basic medicines: If you have a headache, you buy one tablet, not ten, even if you are richer.
Matchboxes: A family uses about the same number each month, whether income rises or falls.
Tap water: Most people use a fixed amount daily, not much more if they earn more.
Why it matters
Helps businesses: Companies know some products will always have steady demand.
Government planning: Helps plan for essential goods during tough times.
Exam questions: Often asked to name goods whose demand does not change with income.
Common mistakes
Thinking all goods change with income: Not true. Some goods, like salt, do not.
Confusing price with income: Here, we are talking about income, not the price of the good.
Remember it
Necessities like salt or medicine: demand does not change even if income does.
Check yourself
If your family's income doubles, will you buy twice as much salt? Why or why not?
No, because salt is a necessity and you only need a fixed amount.
What type of goods have demand that does not change with income?
Necessities or income-inelastic goods.
Why does demand for luxury cars increase when income rises?
Because people can afford to buy more luxury items when they have more money.
Quick recap
Some goods' demand does not change with income.
These goods are called necessities or income-inelastic goods.
Examples include salt, matchboxes, and basic medicines.
For most goods, demand changes with income, but not for necessities.
