§ Mr. Neil HamiltonTo ask the Chancellor of the Exchequer if he will estimate the additional yield of class 1 national insurance contributions in 1988–89 if the upper earnings limit on employees' contributions were(a) abolished or (b) increased to the earnings level at which a single-earner married couple would start to pay income tax at 40 per cent. on the assumptions that the couple had the average amount of investment income, taxable benefits in kind and mortgage interest relief for a single-earner couple at that income level and that there was statutory indexation of the 40 per cent. tax threshold in the 1988 Budget.
§ Mr. Norman LamontThe direct revenue yield in a full year at 1988–89 levels of income of(a) abolishing the upper earnings limit on employees' national insurance contributions and (b) increasing the upper earnings limit to £410 per week is estimated to be about £1,400 million and £500 million respectively. The estimates otherwise assume the national insurance rate structure for 1988–89 set out in chapter 3 of the 1987 Autumn Statement and indexation of the current income tax bands and allowances to 1988–89 levels as in table 4£1 of the Autumn Statement. They make no allowance for possible changes in taxpayers' behaviour.