These indicators are classified into three major categories:

1. real estate development and approval
2. new housing sales and second hand housing offered;
3. construction expenditures

Construction indicators are recurring and very sensitive to the level of interest rates and the level of disposable income. Sometimes, the bank issue low interest rates also won’t help to generate a high demand for housing. As happened in U.S. 1990, low mortgage rates only cause housing increased marginally, due to the low employment rate in a weak economy period. Housing level about between one and a half and two million units indicates a strong economy, whereas around one million units imply that the economy is in downturn.