Hedonic models are commonly used in real estate appraisal and real estate economics, as houses have a variety of easily-measured traits (Such as the number of rooms, overall size, or distance from certain amenities) which make them more amenable to hedonic regression models than most other goods. Hedonic regression is also used in consumer price index (CPI) calculations, where it is used to control for the effects of changes in product quality. Price changes that are due to substitution effects are subject to hedonic quality adjustments.