The size of government liabilities is only now becoming apparent, but the choice of discount rate is crucial in estimating these. Historically this has been set using Green Book methods and FRS17 accounting standards, but now government is moving to using a rate based on hoped-for economic growth of 3% plus inflation. The more prudent rate to use would be the much lower gilt rate of under 1% – the government’s long-term index-linked cost of borrowing. Use of the 1% rate would show liabilities more than £2 trillion higher, and these will increase as the effects of using the higher discount rate ‘unwind’. Furthermore, the overoptimism from using a high discount rate can lead to poor policy decisions in pensions, government spending and strategic planning.