The constitution of a corpus of long - term economic statistics for Vietnam is a long and arduous task, but one that is possible and likely to be fruitful, especially if the investigations avoid limiting themselves to the compilation of statistics from annual reports but also examine the different public and private sources in the plethora of extant archives. It is indispensable to compare the macro - economic series which come from annual reports and the micro - economic or regional information which come from monographs, from anthropological or sociological studies, and from reports by local colonial administrators or by managers of companies or consulates. Only in this manner can one extract original information which would permit acceptable estimations of series which are missing or manifest lacunae. Thus, the agricultural production and rural population can not be evaluated except by a compilation of information adjusted by province or prefecture. Under those conditions, it would be possible to take into account the underestimationís and discontinuities in the series, caused by politico - military or natural disasters, and even the imperfections and ruptures in the working of the statistical apparatus.
Diversifying the sources offers a token of reliability for series which will emerge from a retrospective estimation. However, this method is made shakier by the absence of reasonable references, due to the impact of the Japanese occupation and especially of the Indochina War and then the Vietnam War. One would have to proceed with a double extrapolation. The South was less troubled by the war until 1954 and the statistical apparatus was a little less influenced by political considerations between 1954 and 1975. Researchers should correct the series for certain regions not under the control of the colonial administration between 1946 and 1954. This concerns especially the North where administrative control was weak. These resulting numbers could then be compared to the numbers collected during the 1930s, the last years of the modern era when the information remained fairly homogenous. Building on this groundwork, one could attempt to reconstitute series with gaps through retrospective extrapolation or interpolation.
This implies, over and above international co - operation between researchers, an effort to create a dialogue between archivists, historians, anthropologists and economists who will see results pertinent to their respective fields materialise from their mutual efforts : identification of different archives dispersed by political and military events, the knowledge of the quantitative economic environment surrounding economic, political and social facts, the comprehension of long - term economic dynamics and the possibility of international comparisons which could lead to new considerations regarding Vietnam's ability to catch up in a changing Southeast Asia at the end of the twentieth century.