Readers Question: Could you please help me understand why high debt as a big percentage of GDP is bad, or at what point does it becomes bad? Japan is at something like 194%, and the UK at 500% (counting all debts and liabilities). Both countries are still waking up every day and going about business (I guess). What do those comparisons of debt to GDP actually tell me?
Firstly, the statistic for UK at 500% looks like UK external debt. Or more likely it could refer to the total UK debt i.e. Private + Public debt. See: UK Total Debt.
194% looks like Japan’s government debt, though Japan government debt is now over 220% of GDP. Total Japanese debt is similar to the UK.
The government often need to know and decide at which level public sector debt is a problem.
For example, at the moment, Public sector debt in different countries is:
- Japan 225% of GDP
- UK 64% of GDP (2012) (excluding financial sector intervention
- Portugal 83% (2010 est. of GDP)
- Spain 63% (2010 est.)
- see: list of debt by Country
Also, if you look at historical national debt, the UK has had much higher debt levels. In the early 1950s, UK debt was over 200% of GDP. Does that mean the UK could triple its current government debt? Well, probably not. Circumstances are different in 2012 to the early 1950s.
From these statistics, you might expect Japan to be in the greatest difficulty because it has by far the highest levels of debt.
Yet, markets are not really concerned about Japan public sector debt levels. Bond yields on Japanese government debt are very low. See: Why can Japan borrow so much?
However, markets are very worried about government debt levels in Portugal and Spain. Bond yields on Portuguese and Spanish debt have risen significantly in the past few months. Bond yields on Portuguese debt at the end of 2011 was 13%