Demand Curve

The market demand curve shows the total quantity of a product all buyers will buy at each price, assuming everything else stays the same.

The individual demand curve visually shows how much of a commodity a single consumer is willing to buy at different prices. It always slopes downwards from left to right, representing the law of demand: as the price decreases, the quantity demanded increases (and vice versa).

The demand curve is a graph that shows how much of a good a consumer will buy at different prices over a given period, holding all other factors constant. It visually demonstrates the law of demand: as price decreases, the quantity demanded increases, and vice versa.​

• A demand schedule lists quantities demanded at various prices.
• By plotting prices (Y-axis) against quantities demanded (X-axis), each price-quantity pair forms a point on the graph.
• Connecting these points forms the demand curve, which usually slopes downward from left to right, representing the inverse price-quantity relationship.​

• Demand Curve: Graphic representation of quantity demanded at various prices.
• Law of Demand: Inverse (negative) relationship between price and quantity demanded.
• Quantity Demanded: Number of units a consumer wants at a specific price.

1) The market demand curve is made by adding up the quantities demanded by all individuals at each price. This is called horizontal summation.

2) For each price, add the amounts each person wants:

Example:
At ₹100 per kg:

• Household A = 1 kg
• Household B = 2 kg
• Market total = 3 kg (1 + 2)

At ₹80 per kg:

• A = 4 kg
• B = 5 kg
• Market total = 9 kg (4 + 5)

• Helps businesses forecast sales at different prices.
• Assists policymakers in understanding how taxes or subsidies might affect consumption.

• The vertical (Y) axis shows the price (in ₹).
• The horizontal (X) axis shows the quantity demanded (in kgs).
• As you move from point D (high price, low quantity) to the other D (low price, high quantity), the curve slopes downward, indicating an inverse relationship.

Think of a fruit market. If every family shares how much they’ll buy at each price, and you add everyone’s quantity for each price, you have the market demand—total apples sold at each price.

Imagine buying ice cream. At a high price, you may buy only one scoop. If the price drops, you might buy several scoops. This behaviour—buying more when prices fall—is shown on the demand curve.

• The market demand curve is the sum of all buyers' demands at each price.
• It slopes downwards: lower price → higher quantity demanded.
• Useful for market analysis and price setting.

If only Amar is shopping, his choices at different apple prices create his demand curve. If Amar, Ali, and Alex all shop, the market demand curve sums their choices, showing total apples bought at every price.​

• The demand curve for an individual consumer slopes downward from left to right, demonstrating that lower prices lead to higher quantities demanded.​
• Demand is affected by individual preferences, income, and prices of related goods (substitutes and complements).​
• Only price changes cause movement along the demand curve; other factors cause the curve to shift.

• The demand curve represents the law of demand visually.
• There are two types: individual and market demand curves.
• The market demand curve is derived by summing individual curves at each price.
• Movements along the curve are due to price changes; curve shifts are due to outside factors.