Which factor does NOT typically affect demand?

The factor that does not typically affect demand is related to variations in supply costs. Demand refers specifically to the consumers' willingness and ability to purchase goods and services at different price levels. While changes in consumer income, the number of consumers in the market, and consumer tastes and preferences directly influence how much of a good people want to buy, supply costs are related to the production side of the market.

Supply costs impact the quantity of goods that producers are willing and able to offer at various prices, thereby influencing the supply curve rather than the demand curve. When supply costs rise or fall, it may lead to shifts in the supply curve, altering equilibrium prices and quantities in the market. However, this does not change the consumers' inherent desire or ability to purchase the good itself; thus, it does not directly affect demand.