A real-estate bubble or property bubble is a type of economic bubble that occurs periodically in local or global real estate markets, and it typically follows a land boom or reduced interest rates. A land boom is a rapid increase in the market price of real property, such as housing, until prices reach unsustainable levels and then decline. Market conditions during the run-up to a crash are sometimes characterized as "frothy." The questions of whether real estate bubbles can be identified and prevented, and whether they have broader macroeconomic significance, are answered differently by different schools of economic thought, as detailed below.