SEMAINE D’ETUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. tuations, technological changes and sociological pressures which affect the labour market. The picture which emerges from unemployment statistics we take to represent a past state of technology, and the picture which emerges from the statistics of vacancies we take to re- present a future state. Our estimates for 1961 are obtained by giving each picture equal weight. We found that some skills, namely managers, qualified manpower, technicians and operatives, appear to have moved in line with the demands of technology over the 1950's. We then worked out the weights that would best reproduce the 1951 position for these four skills and found that they were 0.9 for unemployment and o.1 for vacancies. We then reversed these weights and applied them to all skills to obtain a first approximation to the spectrum of skills for 1970. Obviously this is a very crude method of estim- ation, and we have only used it as a first device to feel our way into the subject. We now have for 1970 a provisional vector showing the distribution of labour by skills and, from the calculations described under e) above, a provisional vector showing the distribution of labour by industries. If we consider an employ- ment matrix with skills in the rows and industries in the co- lumns, we see that these two vectors provide its marginal totals for 1970. We can now try to fill in this matrix for 1970 by the RAS method, using the corresponding matrix for 1961 as a starting point and the 1970 vectors as controlling totals. We have carried out this exercise and found that con- vergence is almost immediate. Since the marginal totals were estimated independently, this result suggests that it may be possible to derive a simple relationships between changes in productivity and tbe skill distribution of the labour force in each industry. But at present this is a surmise whose verifi- cation must await further analysis. 1] Stone - pag. 734