§ Mr. Frank Field
To ask the Secretary of State for Social Security what would have been the cumulative loss of revenue to the national insurance fund if the employee contribution rates for 1978–79 had remained in force up to 1996–97. 
§ Mr. Heald
If the employees' contribution structure, rates and level of contracted-out rebates in force in 1978–79 remained in force from 1988–89 up to 1996–97, about £26.5 billion less would have been paid into the national insurance fund. There is insufficient data to provide a reliable estimate in respect of the period prior to 1988–89.
Government Actuary's Department.