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).[14] 

While it may be free, there is no one monitoring the barter ads, so you must be aware of potential Craigslist scams, and realize that you are always at risk when it comes to meetups and exchanges. For example, about a year ago, I arranged to trade massage gift certificates for housecleaning. Since the individual was coming to my home, I was more nervous than usual. However, she offered good previous references, and we  arranged for a time to meet when my husband would be home, in case an odd, unexpected, or even dangerous situation arose.
He would have heard of channels and sandbanks, of natural features of the land useful for sea-marks, of villages and tribes and modes of barter and precautions to take: with the instructive tales about native chiefs dyed more or less blue, whose character for greediness, ferocity, or amiability must have been expounded to him with that capacity for vivid language which seems joined naturally to the shadiness of moral character and recklessness of disposition.
Economic historian Karl Polanyi has argued that where barter is widespread, and cash supplies limited, barter is aided by the use of credit, brokerage, and money as a unit of account (i.e. used to price items). All of these strategies are found in ancient economies including Ptolemaic Egypt. They are also the basis for more recent barter exchange systems.[15]
To try a time bank, search online for one in your local area using How time banks are managed varies according to the region, so it is important (and often mandatory) to attend an initial meeting that explains the general rules of your local chapter. Once you do this, you’re ready to start trading away. Your services and contacts are identified through the local time bank website.
Barter Network Ltd. is a proud member of The International Reciprocal Trade Association, IRTA, which is a non-profit organization committed to promoting just and equitable standards of practice and operation within the Modern Trade and Barter and other Alternative Capital Systems Industry, by raising the awareness and value of these processes to the entire Global Community. IRTA provide all Industry Members with an ethnically based global organization, dedicated to the advancement of Modern Trade and Barter and other Alternative Capital Systems, through the use of education, self-regulation, high standards and government relations. The Board of IRTA consists of Key Players in the Barter Industry, With Patti Falus President of Barter Network Ltd. being the only Canadian who sits on the Board.

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The man who arguably founded modern economic theory, the 18th-century Scottish philosopher Adam Smith, popularized the idea that barter was a precursor to money. In The Wealth of Nations, he describes an imaginary scenario in which a baker living before the invention of money wanted a butcher’s meat but had nothing the butcher wanted.“No exchange can, in this case, be made between them,” Smith wrote.

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, 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.

In 2010, Shannon Lee Simmons had it easy. Though the economy was two years into its recessionary lurch, she had a secure job at Phillips, Hager and North, a boutique Bay Street investment firm. She was 25 years old and earning $55,000 a year, plus bonuses. She had no debt, no kids, and enough disposable income to jet off to Europe with her boyfriend and pay her credit card bills on time. Simmons is driven and effervescent, and has the charming tendency to slip into club-kid slang. Speaking of her time back then, she says: “I was ballin’.”

Adam Smith, the father of modern economics, sought to demonstrate that markets (and economies) pre-existed the state, and hence should be free of government regulation. He argued (against conventional wisdom) that money was not the creation of governments. Markets emerged, in his view, out of the division of labour, by which individuals began to specialize in specific crafts and hence had to depend on others for subsistence goods. These goods were first exchanged by barter. Specialization depended on trade, but was hindered by the "double coincidence of wants" which barter requires, i.e., for the exchange to occur, each participant must want what the other has. To complete this hypothetical history, craftsmen would stockpile one particular good, be it salt or metal, that they thought no one would refuse. This is the origin of money according to Smith. Money, as a universally desired medium of exchange, allows each half of the transaction to be separated.[2]
During economic downturns, when there is a keenly felt shortage of jobs and cash, people have historically adopted barter systems. The world’s most established bartering-style system is Switzerland’s wir: the German word for “we” as well as the abbreviation of Wirtschaftsring, which translates loosely to “economic circle.” In 1934, the economy in Switzerland had tanked—as it had in much of the world. Two businessmen who were facing bankruptcy, Paul Enz and Werner Zimmermann, gathered 15 of their associates in Zurich and hashed out a solution: a mutual credit system.