On the basis of the existing historical narrative, it is difficult to discern what factors, on average, facilitated or hindered fair-housing legislation, let alone how much those factors mattered.

• 在原有的历史描述的基础上,想要辨别是哪些因素推动或阻碍了公平住房立法是很困难的,更别说了解这些因素都起到了多大的作用了。