LONDON – The current value of the US government’s unfunded pension and Medicare liabilities is $46.7 trillion, or roughly two and a half times US GDP. Other estimates put that figure much higher. In the United Kingdom, a similar calculation by the Adam Smith Institute yields a £1.85 trillion ($2.34 trillion) “hidden debt time bomb.” And the situation in Switzerland, France, Belgium, Germany, Austria, and Spain is little different. It seems that all advanced economies are facing public-finance trouble ahead