Which of the following correctly explains the notion of consumer surplus?

Correct option is A

Consumer Surplus is a fundamental concept in microeconomics, especially in welfare economics. It is defined as the monetary benefit consumers receive when they pay less for a product than the maximum price they are willing to pay.

Mathematically, it is:

Consumer Surplus = Willingness to Pay (WTP) - Actual Price Paid

For example, if a consumer is willing to pay ₹100 for a product but purchases it for ₹70, then the consumer surplus is ₹30. When this surplus is aggregated across all consumers in the market, it reflects the total net benefit to society from the consumption of the good.

Information Booster:

• The concept was introduced by Alfred Marshall.

• Graphically, consumer surplus is the area under the demand curve and above the price line up to the quantity purchased.

• It reflects consumer welfare and helps evaluate the effects of price changes or government policies.

• A decrease in price increases consumer surplus.

• Used to measure welfare effects of taxation, subsidies, and price discrimination.

• Under perfect competition, consumer surplus is maximized since price equals marginal cost.

Additional Knowledge:

(b) The difference between what consumers are willing to buy for a given quantity of goods and services and the quantity they actually buy - This describes a mismatch in quantity demanded vs. quantity purchased, not price. Consumer surplus is about the price willingness and actual price paid, not quantity discrepancies.

(c) The difference between what consumers are willing to plan to buy for a given quantity of goods and services and the quality they actually buy - This option mixes planned buying and quality, which are unrelated to consumer surplus. Consumer surplus is not based on quality but rather on price expectations vs. actual price.

(d) The difference between total utility and addition to total utility from goods and services the consumers buy - This is mixing total utility and marginal utility concepts. Consumer surplus is not the difference between TU and MU, though both are related in marginal analysis.