The Tiv people of northern Nigeria organize their local system of exchanges into separate spheres. While Tiv people regularly exchange with each other, not every objects can be exchanged for any other object, and each exchange is conducted in a certain manner and only with certain people. The model of spheres of exchange is an attempt by Paul Bohannan (1955) to explain these rules. Basically the spheres are:

The first sphere of exchange applies to objects of subsistence, foodstuffs, some livestock, some tools, and utensils. Tiv consider this to be the most open form of exchange, and use a word which can be translated as 'market.' Anyone can exchange products with anyone, and once the transaction is complete, the two parties need not have anything to do with one another. Notably, Tiv prefer not to 'market' with friends and kin, because it interferes with the social role they have to play in this situation. The second sphere of exchange concerns exchanges of prestigious items, such as white, woven tugudu cloth and brass rods. These cannot simply be exchanged in 'market' trade. They can only be exchanged for each other and for similarly prestigious items. In this category also once fell slaves. Slaves could not be bought and sold for food, but rights to the labor of a slave could be transferred in exchange for a certain amount of brass rods and cloth. The final sphere of exchange is not what one would normally consider part of the domain of economy or transaction. The third sphere is the sphere of marriage. Tiv frown upon marriage by purchase, or brideprice, or dowry for that matter. A good marriage is when a woman marries a man of another kin group, goes to live with that group, and then later her husband's sister or other female member of his group goes to marry one of the wife's brothers. In other words, marriage is ideally an exchange between groups and people are the gifts. But unlike the second sphere, in which people can be exchanged for objects, marriages can only result from a relationship of exchange in which one person is substituted for one person.

Exchange spheres are ranked. The first concerns goods which are lower in value than those of the second, and so on. Bohannan also described ways that Tiv individuals acquire wealth in this system. The proper way to wealth for Tiv is 'investment', not in the sense of reaping more wealth, but by turning lower-ranked items into higher-ranked items, and by improving one's relative position in the community. They describe it with a proverb of a man who owns a chick, raises it to maturity, and then gets the eggs, raises them, trades them for goats, and so on. In other words, you can gain wealth by making use of natural forms of growth and by converting this into superior, more prestigious items. If, for instance, someone only has abundant foodstuffs, but doesn't invest this in prestigious items, they are foolish. If someone attempts to acquire brass rods with lots of foodstuffs, this person would be seen as smart, savvy and ambitious. They feel bad for the person on the other end of this exchange; they may be well-off, but they are losing prestige in this exchange. This person takes priceless valuables which he has probably held for many years and give them up for food.

At the time Bohannan was doing his research, Tiv was part of a colonial market economy, and Tiv people often made use of the state's money in market exchanges. Money was at that time something was used widely but attracted great shame because it was believed to be a violation of the system of spheres. Bohannan notes that initially money was classed on the lowest end of the ranked scale of value, in a fourth sphere alongside foreign goods (Bohannan 1955, 66). Money could not be used to buy prestige goods. Like many of the Tiv people from whom Bohannan learned about spheres of exchange, Bohannan foresaw a time when the logic of money would overwhelm the system of spheres. The Tiv system was multicentric, but general-purpose currency would collapse all the spheres into a unicentric system in which everything had a price expressed in money, and all exchanges would be market exchange.

Bohannan's prediction has turned out to be both true and false. Some have argued that money did not automatically eliminate the distinctions among spheres and give everything a single value in money (Parry and Bloch 1989, 13–14). As with many encounters between capital and community, the arrival of state-backed, commodity money (i.e. cash money) has had unexpected results. While Tiv are much more integrated into a national market economy and the global economy, they still value many of their prestige goods. Tugudu cloth in particular has become a valued form of local craft.

Bohannan's own model itself has been challenged. Janet Hoskins notes that people of Sumba in Indonesia have historically had a similar system of spheres of exchange, but that when they adopted money during Dutch colonial rule, it was only used in exchange for items in their lowest sphere (Hoskins 1997, 186–188). Many scholars, such as Jane Guyer (2004), have argued that the prestige goods which Bohannon said were restricted from the lowest, 'market' sphere, were actually themselves used as local currency in transactions with peoples outside of the community. Restricting them to their own sphere was a way for people to maintain control over them. Changes in the local system of exchange did not come, in that sense, from the power of money to establish a single quantitative measure of value, because prestige goods could already play that role in certain areas. The real change came when the colonial state excluded local and regional forms of money from the new economy.

This page has recently been updated to clarify the status of money and money-exchange in Tiv in the time Bohannan describes in his ethnographic works. Money was used widely but appears to have attracted the same shame that any other downward conversion across spheres did. Money was not simply classified in the third lowest sphere, but Bohannan suggests that it formed a lower fourth sphere of its own (but cf. Hoskins 1997, 186–188). See the page history for the precise changes.

Bohannan, Paul. 1955. “Some Principles of Exchange and Investment among the Tiv.” American Anthropologist, New Series, 57 (1): 60–70.

Guyer, Jane I. 2004. Marginal Gains: Monetary Transactions in Atlantic Africa. Chicago: University of Chicago Press.

Hoskins, Janet. 1997. The Play of Time: Kodi Perspectives on Calendars, History, and Exchange. Berkeley: University of California Press.

Parry, Jonathan, and Maurice Bloch. 1989. “Introduction: Money and the Morality of Exchange.” In Money and the Morality of Exchange, edited by Jonathan Parry and Maurice Bloch, 1–32. Cambridge: Cambridge University Press.