1. Liquefaction mitigation is not sufficient for relatively inexpensive structures such as private houses, river levees and embedded lifelines.
2. Similarly, private residential land that is situated on earth fill is subject to significant seismic hazard.
3. In spite of ongoing efforts, there is not yet good technology to improve the bad subsoil under existing structures. This point is in clear contrast with the situation of new construction.
4. Classification of seismic performance or seismic safety on the basis of a simple index can improve the people’s recognition of the quality of properties.