The "housing market index" is a statistical model used to track the demand for new homes. It is compiled with data from a sample of home builders, and it varies over time with changes in the housing market. The index runs has a range of 0-100, with 50 being the benchmark for "average" demand for new homes. Housing market indices can cover the country, or they may cover a state or region, and they are important indicators of economic trends in the area.