four major reasons for this irregularity as ‘intermittent, frictional, technological and seasonal’ unemployment, quite apart from the general unemployment that accompanies fluctuations in the demand for building — fluctuations which are generally agreed to be particularly pronounced and regular. Though these are not, strictly speaking, ‘reasons’, but rather classifications of reasons, and overlapping classifications at that, it is useful to discuss the various causes of irregularity under these headings. Intermittent unemployment stems from such causes as the weather and irregularity of supplies — though those caused by weather merge into seasonal unemployment. This type of in- terruption is indeed unavoidable though its extent and effects can be minimised. Weather-induced interruptions can be reduced through developing a more versatile labour force which can be switched to different tasks, and in the long run by developing techniques of production which, though more costly, allow the continuation of work at least under all but very severe conditions. Supply interruptions depend on the organisation of the contractor and his system of ordering supplies, as well as the efficiency of the supplier institutions, which makes the point that the problems of the construction industry cannot be solved by that industry alone. The implications of this for the workers, the firm and the Govern- ment will be spelled out in more detail in following sections. Most European countries in both capitalist and socialist camps have schemes under which workmen are compensated, at least in part, for time lost due to these factors. Some of these schemes call for full pay for unlimited periods — U.S.S.R. and Switzerland — others call for partial pay for unlimited periods — Poland — while others still call for partial pay for limited periods — Ger- many, France, etc. In some cases work is made up after hours without payment of overtime —France. In some cases this problem is dealt with through a guaranteed wage, which means the workman bears the first loss incurred through such stoppages, but is protected against severe hardship by the fact that his loss cannot exceed a certain amount within a specified period. In all these cases it is assumed that the workman is hired ‘at least’ for the duration of a job. Hiring by the day as is common in Tanzania shifts the whole of the burden of the workmen. It provides little incentive for utilising resources efficiently from a 117