Which of the following factors does not affect demand?

Production costs do not directly affect demand; instead, they primarily influence supply. Demand refers to the quantity of a good or service that consumers are willing and able to purchase at different price levels within a specific period. Factors such as consumer income, preferences, and the number of buyers are relevant to demand because they determine how much of a product consumers desire at a given price.

When consumer income increases, for example, consumers typically have more purchasing power, which can lead to an increase in demand for normal goods. Similarly, changes in consumer preferences can significantly sway demand; if a product becomes more popular, the demand for it will increase. The number of buyers in the market also impacts demand—more buyers generally lead to higher demand for a product.

In contrast, production costs affect the supply side of the market. If production costs rise, suppliers may produce less of a good at the same price, which can decrease market supply. However, this change in supply does not influence how much consumers want to purchase; hence, it does not affect demand directly. Understanding the distinctions between these concepts is vital for analyzing market dynamics in macroeconomics.