Mary Douglas has distinguished two kinds of primitive currencies, general purpose currencies, and primitive rationing systems. She describes Bohannan's analysis of the Tiv copper rod currency as the best example of a primitive rationing system. According to Bohannan, there were three levels of exchange in the Tiv economic system: everyday consumer goods in the lowest level, rods and prestige goods in the middle level, and wives and women in the highest level. Because rods were not divisible they were too valuable to be used for lower order transactions, and so ordinary people could not accumulate rods to purchase prestige goods. Nor could rods be accumulated to buy wives, the most desired and status-conferring possession in the system. Thus the rod currency reinforced the status divisions in Tiv society, and to Douglas appeared to be coupons in a system which rationed status.
However, despite Bohannan's analysis, there is ample evidence to show that elsewhere in the Cross River rod currency area, rods were divisible into wires which were used as a medium of exchange for everyday consumer goods, and were clearly a general purpose currency. By accumulating wires, which could be exchanged for rods, prestige goods and offices could be bought.
Because it was a general purpose currency, the rod facilitated credit, and the accumulation of capital in the capitalistic commercial system. Yet capitalistic means of production in crafts or agriculture were not adopted until the late 1870s, with the attempt to develop cocoa as a cash crop, which failed due to the unsuitability of the area. Instead surplus capital was converted into slaves, because they were wealth in themselves, and enhanced their masters' security and status.