asked Her Majesty's Government:Whether they will tabulate the successive official estimates made in the period 1965 to 1980 on the impact of the North Sea discoveries of gas and oil on:

The main source of official estimates of the impact of North Sea oil and gas on the United Kingdom economy is the series of articles in the Treasury's Economic Progress Report on the following dates:

July	1976
August	1977
August	1978
October	1979
July	1980

Information on some of these subjects has also been published in Department of Energy's publication Development of oil and gas resources of the United Kingdom (the "Brown Book"; 1975 to 1980 editions) and the CSO's publication United Kingdom Balance of Payments (the "Pink Book"; 1978 to 1980 editions). An article on North Sea oil and gas in the United Kingdom balance of payments since 1970 appeared in the Bank of England's Quarterly Bulletin for September 1979.The estimates of the impact of North Sea oil and gas on various parts of the United Kingdom economy have been made using a variety of different price bases and, in some cases, using different methodologies and assumptions. It would not be practicable, without disproportionate cost in time and effort, to produce a table which compared all these estimates on a common price basis using common methodology.

asked Her Majesty's Government:Whether they will estimate the potential gain to British Airways in 1981–82 of the introduction of a security levy charge for non-passenger carrying aircraft of 50p per tonne or part thereof of landed weight.

The information necessary for making such an estimate could only be obtained at disproportionate cost.

asked Her Majesty's Government:When they expect centralised searching to be introduced at Terminal 3, Heathrow Airport and with what actual saving in (

For estimates of savings in manpower and costs I would refer the noble Lord to the reply I gave him on 11th November (Official Report, col. 1357). As I explained then, the implementation of centralised searching is a matter for the British Airports Authority, in consultation with the other interests concerned. The date of introduction of centralised searching and the actual savings in manpower and costs will depend upon the result of these consultations.

asked Her Majesty's Government:Whether they are satisfied with the undertakings given by Japan for the progressive reduction of Japanese exports of motor vehicles to the United Kingdom and whether they will give figures showing promise and performance.

There is an understanding between the Japanese Automobile Manufacturers' Association and the Society of Motor Manufacturers and Traders that the Japanese manufacturers will exercise prudence in their sales to the United Kingdom. This has kept their annual share of the United Kingdom market at between 9 and 11 per cent. for the five years from 1975 to 1979. Shipments are lower this year than in the corresponding period of 1979, but the share of the reduced United Kingdom market held by vehicle imports from Japan this year is higher and my right honourable friend the Secretary of State for Trade has made known his concern to the Japanese Government.House adjourned at twenty-one minutes after six o'clock.