Concept of Demand

In everyday life, we often use “desire”, “want”, and “demand” as if they mean the same thing. But in economics, only demand refers to what people will actually buy—not just what they wish for.​

• Desire: Just wishing for something (e.g., dreaming of buying a car).
• Want: Desire plus the plan and resources to obtain it.
• Demand: Want plus willingness and ability to pay a specific price at a certain time.

• "Want is effective desire for particular thing which expresses itself in the effort or sacrifice necessary to obtain them." – Peterson

• "The demand for anything at a given price is the amount of it which will be bought per unit of time at that price." – Prof. Benham
• "By demand, we mean the quantity of a commodity that will be purchased at a particular price and not merely the desire of a thing." – Hansen
• "The demand for a particular good is the amount that will be purchased at a given price and at a given time." – Veera Anstey

Demand = Desire + Willingness to Buy + Ability to Pay

• Always tied to a price (“How many units at ₹50 each?”)
• Must specify a period (“per week”, “per month”)
• Effective desire—demands must be backed by buying power
• Not for free goods (no demand for air or sunlight)

• Meaning: Microeconomics studies the behaviour of individual consumers, firms, and markets.​
• Demand (Micro): The quantity of a specific commodity that a single person or household is willing and able to buy at a particular price during a specific period.
• Example: If Usha buys 2 kg of apples every week at ₹60 per kg, her demand is microeconomic.

• Meaning: Macroeconomics examines the economy as a whole—total demand, income, employment, and growth for a country.​
• Aggregate Demand (Macro): The total amount of goods and services demanded in an economy at a given price level during a set time period.
• Example: The aggregate demand for cars in India last year includes all cars bought by everyone—firms, households, and the government—nationwide.

• Micro: Like looking at one slice of pizza (one consumer’s behaviour).
• Macro: Looking at the whole pizza (the entire economy’s behaviour and choices).​
• Micro demand is “my demand for tea today”; macro demand is “national demand for tea this year”.

• Micro demand = individual level; macro demand = whole economy (aggregate) level.
• Both levels must mention price and time for demand to make sense.
• Demand is always a “flow” concept—measured as so much per time period.