Adding value to model portfolios

More and more often, the starting point for asset allocation advice for a client is a model portfolio selected from a range prepared in advance by a product provider or specialist investment advisory firm. That is perfectly understandable, and I fully appreciate the reasons why advisers take this route. It is said 90 per cent of returns come from asset allocation, while only 10 per cent from stock selection, but this is a retrospective statistic. Asset allocation is hellishly difficult, so relying on the brain power and number-crunching capability of a specialist is sensible. Moreover...