Income Tax Mr. Silvester asked the Chancellor of the Exchequer if he will list those provisions relating to income tax which allow a specific exclusion, exemption or deduction from gross income or which provide a special credit or a deferral of tax liability giving for each his estimate of the value of the concession. Mr. Robert Sheldon I will let the hon. Member have a reply as soon as possible. Mr. Hardy asked the Chancellor of the Exchequer what is his estimate of the cost to the Exchequer of a further reduction of one penny in the rates of income tax. Mr. Robert Sheldon , pursuant to his reply [Official Report, 27th April 1977; Vol. 930, c. 365], gave the following information:The estimated cost for 1977–78 of reducing the basic and higher rates of income tax by one percentage point is about £520 million.