PRINCIPAL FEATURES OF INTERNAL TRADE
The information available on the important topic of internal trade is of uneven quality and some of it is fragmentary. There are various reasons for this comparative paucity of information. Internal trade does not pass international boundaries at which its composition and volume are recorded for customs purposes, and it is not centred on a few ports where trade statistics could be recorded for purposes other than customs control. Moreover, this trade represents a section of the economy which has no direct contact with European traders or Western methods. Its organization is often closely connected with local customs and with the family and tribal system; this makes for additional difficulties in the collection of information. Lastly, unlike external trade, it has not, until recently, presented serious economic and political problems to administrators, and they have not been particularly concerned with it.