Is the US (and a number of other high-income countries) on the road to fiscal armageddon? Are recent jumps in government bond rates proof that investors are worried about fiscal prospects? My answers to these questions are: No and No. This does not mean there is no reason for worry. It is rather that there are powerful arguments against fiscal retrenchment right now and strong reasons for welcoming recent moves in the bond markets.

Last week, the Financial Times carried two columns arguing that the US fiscal path was unsustainable, one by Stanford University's John Taylor and the other by the Harvard historian Niall Ferguson. The latter, in turn, was a comment on a debate with, among others, the New York Times columnist and Nobel laureate Paul Krugman at the end of April.

On one point all serious analysts agree: public debt cannot rise, relative to gross domestic product, without limit. To embark on fiscal stimulus in the short run, one must be credible in the long run.