Internationally, a general rule of thumb is that a reasonable price-to-income ratio should not exceed 5.1. That is to say that if a family didn't eat or drink or spend money on anything but their home, it would take no more than 5.1 years of their income to pay for it.
根據國際比較，合理的「房價所得比」不應該超過 5.1，也就是一個家庭若不吃不喝，最多以 5.1 年的收入就應足夠付清購屋的款項。