asked the Chancellor of the Exchequer whether he will provide information on the net income after income tax, national insurance contributions and child benefit at (a) actual prices and (b) constant (April 1985) prices of typical household units (i) single, (ii) married couple, (iii) married couple with two children, (iv) married. couple with four children whose gross income is at (x) the lowest decile, (y) the median and (z) the highest decile for each year since 1978–79.
[pursuant to his reply, 10 May 1985, c. 533]: Information in the following tables is based on estimates of earnings for those in full-time work paid at adult rates, with pay unaffected by absence. Estimates are based on information from the new earnings surveys. Earnings data for April 1985 will not be available until October 1985.Income tax rates and allowances for April 1979 are those specified in the Finance Act 1979, later replaced by those announced in June 1979; for other Aprils, they are the rates and allowances for the financial year immediately following. Taxpayers are assumed to have no reliefs or allowances other than the appropriate personal allowance. National Insurance contributions are at the contracted-in rate.The calculations take no account of means tested benefits to which those at the lowest decile may be entitled. Changes in the purchasing power of net earnings have been calculated by reference to movements in the general index of retail prices between Aprils.