ONCE upon a time, countries jealously guarded their credit ratings. Before the 2010 British election, George Osborne, soon to be the chancellor of the exchequer, emphasised the importance of cutting the budget deficit in order to maintain the country’s top AAA rating.

But despite the spending cuts and the tax increases he imposed, Britain was downgraded in 2013. There are only 11 countries with AAA status, according to Fitch, a rating agency, down from 16 in 2009. By value, only 40% of global sovereign debt has the highest rating, down from 48% a decade ago.

There has been an even more dramatic downward trend in corporate debt ratings. There were 99 AAA-rated American corporations in 1992, according to S&P Global, another ratings group; now there are just two. That trend is linked to the tax deductibility of interest: in terms of tax efficiency, it has made sense to increase the amount of debt, and reduce the equity, on the balance-sheet.

Clearly, at the sovereign level, the deterioration has been driven by the global financial crisis, which dented both economic growth and tax revenue. But with bond yields very…Continue reading