The main reasons for this seem to be that most investment trusts have lower charges than most unit trusts, nearly all can be bought at a discount to their asset value and, because they are closed funds, they do not have to hold cash to cover possible redemptions.Furthermore, unlike unit trusts they are allowed to retain up to 15 per cent of their investment income in a revenue or income reserve account so when dividends are rising fast they can put some aside to help them over periods when dividends are static or falling. Over 30 of them have, therefore, managed to increase their dividend every year for the past 10 years or so by dipping into reserves. So this type of trust makes an ideal investment for trustees. Over the past 10 years, for example, Glasgow income, which yields over 5 per cent a year, has more than doubled its capital value and with dividends reinvested has shown a total return of more than four times its original investment over the 10 years to October 1 2006. Over the same period trusts such a JP Morgan Fleming Mercantile and RIT Capital Partners have shown similar results but have lower yields. There seems to be just one disadvantage that investment trusts have compared with unit trusts and that is that the discounts might vary and at times some well managed investment trusts’ share prices stand at a premium to their asset value. Because of the stiff competition, and for higher levels of better publicity, some unit trust groups tend to hire the very best investment managers. Some of the groups who do this include New Star, JO Hambro, Artemis and Axa Framlington.