Your mortgage payment is constant through time but the fraction of it that goes to paying off principal versus interest changes through time and it just changes as dictated by this formula.

抵押贷款每月还款是固定的,但是其中本金和利息的比例关系,会随时间而改变,这是由这个公式所决定的

耶鲁公开课 - 金融市场课程节选

But if most people who are good borrowers, who know what they're doing, want these, they want a conventional thirty-year mortgage because it will fix a mortgage payment for the rest of the thirty years and you have nothing to worry about.

但是如果大多数人是优质借款人,他们知道自己在做什么,他们会选择普通30年期抵押贷款,因为在剩余的30年时间里,抵押贷款的偿付是固定的,你不需要为它担心

耶鲁公开课 - 金融市场课程节选