SEMAINE D'ÉTUDE SUR LE ROLE DE L’ANALYSE ECONOMETRIQUE ETC. ~ lete matrix for our base year, 1960, is given in detail in [8]; a summary version for 1962, showing the totals within each class, is given in table I below. For obvious statistical convenience we have keyed in our main totals to the official estimates of national income and expenditure [48]. At certain points, however, we have de- parted from the treatment followed in these estimates. The most important difference lies in the fact that we define con- sumers’ durables not as consumption goods but as fixed assets. This means that in our treatment these goods are bought on capital account and their consumption is measured by depre- ciation. Nevertheless, our estimates of total private consump- tion plus net investment in consumers’ durables are equal to the official estimates of consumers’ expenditure. As can be seen from table 1, the accounts in SAM are simply a logical development of the four national accounts [42], and can easily be reduced back to them by appropriate con- solidation. The use of fifteen classes of accounts instead of four is largely dictated by the need to reconcile different clas- sifications. This can be illustrated by considering the four classes which appear as the first four rows and columns in table 1 and which, taken together, constitute the national ac- count for production. Class I relates to commodities, that is to say products or groups of products which are characteristic of British industries. The entries in column 1 show the sources of these commodities: £44,272 million come from British production and £2,458 million, to which must be added £134 million of customs duties, come from abroad in the form of competitive imports. The entries in row I show the uses to which these commodities are put: £20,943 million go to industries as intermediate product; £13,249 million go to private consumers; £1,761 million go to public consumers; and so on until, as can be seen from the entry in column 15, £5,128 million go to the rest of the world ,1] Stone - pag. 35