UK’s Office for Budget Responsibility:” It is the duty of the Office to examine and report on the sustainability of the public finances”- July 2013 Report
“Our approach to analysing this issue is twofold:
• first, we look at the fiscal impact of past public sector activity, as reflected in the assets and liabilities that it has accumulated on its balance sheet; and
• second, we look at the potential impact of future public sector activity, by examining how spending and revenues may evolve over the next 50 years – and the impact this would have on public sector net debt”.
http://budgetresponsibility.independent.gov.uk/