As Orlove noted, barter may occur in commercial economies, usually during periods of monetary crisis. During such a crisis, currency may be in short supply, or highly devalued through hyperinflation. In such cases, money ceases to be the universal medium of exchange or standard of value. Money may be in such short supply that it becomes an item of barter itself rather than the means of exchange. Barter may also occur when people cannot afford to keep money (as when hyperinflation quickly devalues it).
Michael Linton originated the term "local exchange trading system" (LETS) in 1983 and for a time ran the Comox Valley LETSystems in Courtenay, British Columbia. LETS networks use interest-free local credit so direct swaps do not need to be made. For instance, a member may earn credit by doing childcare for one person and spend it later on carpentry with another person in the same network. In LETS, unlike other local currencies, no scrip is issued, but rather transactions are recorded in a central location open to all members. As credit is issued by the network members, for the benefit of the members themselves, LETS are considered mutual credit systems.
Other countries, though, do not have the reporting requirement that the U.S. does concerning proceeds from barter transactions, but taxation is handled the same way as a cash transaction. If one barters for a profit, one pays the appropriate tax; if one generates a loss in the transaction, they have a loss. Bartering for business is also taxed accordingly as business income or business expense. Many barter exchanges require that one register as a business.
Toronto’s online Freecycle network, where 27,000-plus members can give, and get, things for free, provides a variation on bartering. Last April, Toronto hosted one of its first gift circles, which, as the name suggests, encourage small groups to form gifting communities—groups of 20 that give and take from a pool of goods and services depending on their needs. Torontonians can also swap skills at justfortheloveofit.org, a freeconomy community that spans 174 countries. On the site, members share talents that range from useful (dog walking, yoga instruction, electrical work) to questionable (boycotting, ear candling, loving) to weird (tree whispering, culture jamming, puppet making). When it comes to alternative economies, the creative possibilities are vast, but they all speak to the same desire for something different—anything other than what we have.
No academics I talked to were aware of any evidence that barter was actually the precursor to money, despite the story’s prevalence in economics textbooks and the public’s consciousness. Some argue that no one ever believed barter was real to begin with—the idea was a crude model used to simplify the context of modern economic systems, not a real theory about past ones.