Introduction In March 1978 over 793,000 males classified within manual occupations were registered unemployed in Great Britain. This represented about 10·3 per cent of the number of full‐time male employees then at work in these same occupations. The 1978 New Earnings Survey showed that nearly 58 per cent of the 6·9 million men over 21 in manual occupations worked overtime, on average 10·4 hours in the survey week. From these figures one can calculate that the total number of hours of overtime worked by adult men in manual occupations exceeded 40 millions per week.