There remains enormous unexplained variation in the results of actuarial valuations to determine pension scheme liabilities, says a new report from PricewaterhouseCoopers LLP, based on a recent survey of 90 UK pension schemes with almost £200bn of assets.

Life expectancy predictions differ by up to six years without any correlation to industry, pay, type or location of workforce, or actual scheme experience. Discount rates, which represent the assumed future return of a scheme’s assets, bear little correlation to actual asset allocation, varying by as much as 3% per annum for schemes with similar asset allocations.