Which factor does NOT shift the demand curve?

The factor that does not shift the demand curve is related to production costs. When discussing demand, we refer specifically to the relationship between the price of a good and the quantity demanded by consumers. The demand curve shifts due to external factors that influence consumer behavior, such as changes in consumer preferences, prices of related goods (substitutes and complements), and income levels.

Production costs, on the other hand, relate to the supply side of the market. They affect how much of a product producers are willing and able to supply at various price levels, which influences the supply curve rather than the demand curve. As a result, changes in production costs do not directly affect consumer demand and therefore do not shift the demand curve.

Understanding this distinction helps clarify that demand is concerned with consumer choices, while supply relates to producer costs and decisions.