The income effect describes how an increase in income can change the amount of goods that consumers will claim.
For so-called normal goods, as income increases, so does the demand for them (and vice versa).
In microeconomics, this is reflected in the form of an upward shift in the downward demand curve.
However, this effect may vary depending on the availability of substitutes and the elasticity of demand for the good.
For substandard goods, the income effect dominates the substitution effect and forces consumers to buy more of the good and less of the substitute when the price rises.