If total spending rises from one year to the next, then which of the following must be true?

• A. Either the price of the good has increased, the quantity sold has increased, or both.
• B. The price elasticity of demand must be unit elastic.
• C. Willingness to pay for the good has remained unchanged.
• D. Consumer surplus must have decreased.

Answer: (A)

Verified step by step guidance

1. Understand the relationship between total spending, price, and quantity. Total spending (or total revenue) is calculated as \(\text{Total Spending} = \text{Price} \times \text{Quantity}\).
2. Recognize that if total spending increases from one year to the next, it means that the product of price and quantity has increased. This can happen if the price increases, the quantity sold increases, or both increase simultaneously.
3. Analyze the other options: The price elasticity of demand being unit elastic means total spending remains constant when price changes, so it cannot explain an increase in total spending.
4. Consider willingness to pay: If willingness to pay remains unchanged, it does not necessarily affect total spending directly, as total spending depends on actual prices and quantities sold.
5. Evaluate consumer surplus: An increase in total spending does not guarantee a decrease in consumer surplus, because consumer surplus depends on the difference between willingness to pay and price, not just total spending.