But airlines have another way to ensure that their programmes stay profitable: they can deflate the value of their miles.

他们可以降低里程的价值。

The alternative is, if you're investing in the stock market over time, looking for a longer term, if we are gonna be living with higher inflation for longer, then the value of your debts will be deflated away.

另一种选择是， 如果你随着时间的推移投资于股票市场，寻求更长期的投资， 如果我们要在更高的通货膨胀中生活更长时间，那么你的债务价值就会缩水。