Sir, - The general secretary of the Irish Congress of Trade Unions, Mr Peter Cassells, has said Partnership 2000 will be judged primarily on its effectiveness in sharing the benefits of the economic boom (July 30th, 1997).Public servants worked throughout their lives on the clear understanding that their pensions would be linked in the future to the salary scale for the post they held immediately prior to retirement and that has been the situation up to now.This parity of pension was copperfastened by various Budget statements by Ministers of Finance over the years. Parity is now under threat. Increases to serving officers under the programme for competitiveness and work have not been passed on to pensioners as before.There is no economic need to deprive ex-public servants of the pensions they have paid for by contribution deduction. All public servants played a part in fostering the burgeoning economy. Is it too much to hope that they will now share a little in the so-called tiger economy? - Yours, etc.,Sean Geraghty,Chairperson,Public Service PensionsAction Group,Dublin 13.