The value principle of ______ is the basis of the income approach to appraisal.

The value principle of anticipation is the correct choice, as it underlies the income approach to appraisal. This principle is based on the concept that the value of a property is determined by the future benefits it is expected to generate, particularly through income. In the context of real estate, this means that investors consider not only the current state of the property but also how much income they anticipate it will produce over time.

When appraising an investment property, appraisers project future rental income and factor in expenses to establish a net income. This net income is then capitalized to estimate the property's value. Therefore, anticipation is key because it reflects the buyer's expectation of cash flows from the property in the future, influencing their willingness to pay for it today based on those expected returns.

The other principles, while important in real estate, do not specifically underpin the income approach. Substitution refers to the idea that a property's value is determined by the cost of acquiring an equivalent substitute property. Supply and demand focus on how the availability of properties and the desire for them affect market value. Contribution relates to how much individual components of a property contribute to its overall value. These concepts, although significant, are not fundamental to the income approach as anticipation is.