Which of the following statements about consumer decisions is correct?

• A. A consumer's willingness to pay decreases as they consume more units of a good.
• B. Consumers will purchase a good if their willingness to pay is greater than or equal to the market price.
• C. Consumers always pay less than their willingness to pay for every unit purchased.
• D. Consumer surplus is maximized when the market price equals the consumer's willingness to pay.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the concept of willingness to pay (WTP). WTP is the maximum amount a consumer is willing to pay for a unit of a good. Typically, WTP decreases as more units are consumed due to diminishing marginal utility.
2. Step 2: Analyze the condition under which consumers decide to purchase a good. Consumers will buy a unit if their WTP for that unit is at least as high as the market price, meaning WTP \( \geq \) price.
3. Step 3: Consider the idea of consumer surplus, which is the difference between what consumers are willing to pay and what they actually pay. Consumer surplus is positive when the market price is less than the WTP for the units purchased.
4. Step 4: Evaluate the statement about consumers always paying less than their WTP. This is not necessarily true for every unit, especially the last unit purchased where WTP equals the market price.
5. Step 5: Assess the claim about consumer surplus being maximized when market price equals WTP. Consumer surplus is actually maximized when the market price is lower than WTP for some units, allowing positive surplus on those units.