Income: Changes in a consumer's income can lead to changes in individual demand. Higher income usually increases demand for normal goods, while lower income increases demand for inferior goods. Preferences: Personal tastes and preferences significantly impact what and how much a consumer buys. Price of Related Goods: The demand for a product can be affected by the prices of substitutes and complements. Expectations: Future expectations about prices and income can also influence current demand. For example, if a consumer expects prices to rise in the future, they may buy more now.