A property's value is dropping because the neighboring property's yard is filled with trash. What's this an example of?

This situation is an example of regression, which refers to the decline in value of a property due to negative influences from surrounding properties. In this case, the neighboring property with a yard filled with trash detracts from the overall desirability of the area and, consequently, lowers the value of the property in question.

Regression is significantly linked to the principle of externalities, which states that the value of a property can be affected by the quality of nearby properties. When nearby properties exhibit poor maintenance or undesirable characteristics, such as being cluttered or neglected, it can reflect poorly on adjacent properties, leading to a depreciation in their market value.

Understanding regression is crucial for appraisers, as it emphasizes the impact that external factors can have on property valuation. By recognizing how negative influences from neighboring properties can cause value decreases, appraisers can make more informed assessments of property worth in a given location.