asked the Chancellor of the Exchequer in respect of which categories of employees the Inland Revenue assumes there are taxable earnings arising from

		(a)	(b)	(c)	(d)	(e)	(f)
		Relative export prices (manufactures)	Terms of trade (manufactures)	Relative normal unit labour costs	Wholesale prices of manufactures excluding food etc.	Export prices of manufactures	Import prices of manufactures
1976—
First quarter	…	99·3	100·2	99·0	214·5	110·1	109·9
Second quarter	…	94·4	97·2	91·5	222·0	116·1	119·4
Third quarter	…	95·2	97·3	90·3	230·8	123·1	126·5
Fourth quarter	…	90·4	96·0	82·0	241·2	130·5	135·9
1977—
First quarter	…	96·5	97·9	85·1	254·5	136·2	139·1
Second quarter	…	97·7	99·4	85·0	264·4	141·9	142·8
Third quarter	…	99·9	100·8	84·1	272·9	145·8	144·6
Fourth quarter	…	103·9*	102·5	87·6*	279·1	148·5	144·9
1978—
First quarter	…	107·7*	104·2†	91·3*	286·8†	… 150·3†	144·2†
* Treasury estimate.
† Provisional.
(b), (e) and (f): 1975=100.
(a), (c) and (d): 1970=100.

The series for relative normal unit labour costs is calculated and made available by the Research Department of the IMF. It is based on estimates of potential output in manufacturing which are being revised at present. This may produce consequential revisions to the estimates of relative normal unit labour costs.