Tax Units (Statistics) Mr. Gordon Brown To ask the Chancellor of the Exchequer (1) how many tax units facing a marginal tax rate of 40 per cent. have children;(2) how many tax units have children. Mr. Norman Lamont [holding answers 27 June 1988]: In 1988–89 about 5½ million married couples and single people liable to pay income tax have children. Of these, about 500,000 tax units have a marginal tax rate of 40 per cent. About 1½ million non-taxpayers have children.The figures are based on projection of the 1985–86 survey of personal incomes and the 1986 family expenditure survey and are therefore provisional.