As Daniel Gros recently pointed out, debt that can be rolled over indefinitely at zero interest rates is no debt at all. This is an extreme example; but the closer a fixed interest rate gets to zero, and the longer the maturity becomes, the lower the burden of the stock of debt.
此外，真正影响一国公债负担的是预期年债务维持成本。丹尼尔·格罗斯（Daniel Gros）最近指出，可以以零利率无限展期的债务根本就不是债务。这是一个极端的例子；但固定利率越接近于零、期限越长，债务存量的负担也就越轻。