Those familiar with input-output analysis know well that compilation of input-output tables is a difficult statistical work. The very first input-output tables (e.g. such as those for the United States economy in 1919 and 1929 or for the Federal Republic of Germany in the fifties) were the results of applied economic research. But soon after, official statistical bodies, who understood that input-output tables consistent with national accounts can very much improve the quality of economic statistics, started systematic work in this field. It was also obvious that international exchange of experience can be useful. The two main internatio­ nal fora in which discussion of input-output compilation took place were the international input-out­ put conferences and United Nations bodies. Already at the First International Conference on Input-Output Techniques (Driebergen 1950) several authors analysed the relations between input-output tables and national accounts. The topic was also on the programme of the Second Conference (Varenna 1954). At the Third Conference (Geneva 1961) standardization of input-output statistics was a topic of a panel discussion of eight experts. The relevant papers, which are still of interest, can be found in published conference proceedings.