A perpetuity is an asset or a contract that pays a fixed amount of money each time period, forever.

永续年金是一种财产或者合同,规定在每一时间段内,支付一定数量的货币,直至永远

耶鲁公开课 - 金融市场课程节选

There are not only debt instruments that are payable in currency, but there are also indexed debt instruments that are indexed to the price level so that they give real interest rates.

债券工具,不仅仅是可以支付的货币手段,还是指数利率工具,以指数的形式表达债券的价格水平,显示出实际利率

耶鲁公开课 - 金融市场课程节选