The principle stating that the greater the supply of any commodity in comparison to demand, the lower the value; conversely, the smaller the supply and the greater the demand, the higher the value.
A term that describes how the amount of something and the number of people who want it determine its price. If something becomes less common or more popular, its price will tend to rise. The opposite also is true, the more common something is, or the less that people want it, the lower its price.
In real estate appraisal context, the principle of supply and demand states that the price of real property varies directly, but not necessarily proportionately, with demand and inversely, but not necessarily proportionately, with supply.