It’s hard to answer that without actually seeing a modern gift economy in action. Luckily, modern gift economies actually do exist. On a small scale, they exist among friends, who might lend each other a vacuum or a cup of flour. There’s even an example of a gift economy on a much larger scale, albeit one that’s not always in operation: The Rainbow Gathering, an annual festival in which about 10,000 people gather for a month in the woods (it rotates among various national forests around the country each year) and agree not to bring any money. Groups of attendees set up “kitchens,” in which they prepare and serve food for thousands of people every day, all for free. Classical economists might guess that people would take advantage of such a system, but, sure enough, everyone is fed, and the people who don’t cook play music, set up trails, teach classes, gather firewood, and perform in plays, among other things.
Barter-based economies are one of the earliest, predating monetary systems and even recorded history. People can successfully use barter in many almost any field. Informally, people often participate in barter and other reciprocal systems without really ever thinking about it as such -- for example, providing web design or tech support for a farmer or baker and receiving vegetables or baked goods in return. Strictly Internet-based exchanges are common as well, for example exchanging content creation for research.
Anthropologists have argued, in contrast, "that when something resembling barter does occur in stateless societies it is almost always between strangers." Barter occurred between strangers, not fellow villagers, and hence cannot be used to naturalistically explain the origin of money without the state. Since most people engaged in trade knew each other, exchange was fostered through the extension of credit. Marcel Mauss, author of 'The Gift', argued that the first economic contracts were to not act in one's economic self-interest, and that before money, exchange was fostered through the processes of reciprocity and redistribution, not barter. Everyday exchange relations in such societies are characterized by generalized reciprocity, or a non-calculative familial "communism" where each takes according to their needs, and gives as they have.
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.
Other anthropologists have questioned whether barter is typically between "total" strangers, a form of barter known as "silent trade". Silent trade, also called silent barter, dumb barter ("dumb" here used in its old meaning of "mute"), or depot trade, is a method by which traders who cannot speak each other's language can trade without talking. However, Benjamin Orlove has shown that while barter occurs through "silent trade" (between strangers), it also occurs in commercial markets as well. "Because barter is a difficult way of conducting trade, it will occur only where there are strong institutional constraints on the use of money or where the barter symbolically denotes a special social relationship and is used in well-defined conditions. To sum up, multipurpose money in markets is like lubrication for machines - necessary for the most efficient function, but not necessary for the existence of the market itself."
And that means everything from tuna to stamps to cigarettes has its own unique value in a trade and barter market. — Alexandra Cardinale, Vox, "Why ramen is so valuable in prison," 14 Nov. 2018 European officials were also looking at a barter system that would allow Iran to sell oil, for example to China, and use the proceeds from that sale to purchase goods or technology from Europe. — Laurence Norman, WSJ, "Europe’s Payment Channel to Salvage Iran Deal Faces Limits," 25 Sep. 2018 With unemployment around 9 percent and consumer prices surging, some Argentines are again turning to barter clubs, which first emerged during the collapse nearly two decades ago. — Almudena Calatrava, Fox News, "Argentines seek soup kitchens, barter markets amid crisis," 10 Sep. 2018 This particular search insired Gellar and Laibow to hop on the phone and barter. — Colleen Leahey Mckeegan, Marie Claire, "Sarah Michelle Gellar's Second Act? Disrupting the Food Industry," 18 Apr. 2017 Choco Pies became so prevalent for sale or barter on the streets that North Korea reportedly banned their import to Kaesong in 2014. — Brian Murphy, Washington Post, "The Choco Pie dividend: South Korean firms are drooling at the prospect of business in the North," 17 June 2018 In 1996, amid crippling famine, Ji tried to steal a few pieces of coal from a rail yard to barter for food. — Brian Murphy, BostonGlobe.com, "Could these outspoken North Korean defectors return home?," 11 June 2018 In 1996, amid crippling famine, Ji tried to steal a few pieces of coal from a rail yard to barter for food. — Brian Murphy, BostonGlobe.com, "Could these outspoken North Korean defectors return home?," 11 June 2018 Instead, like many early civilizations, they were thought to mostly barter, trading items such as tobacco, maize, and clothing. — Joshua Rapp Learn, Science | AAAS, "The Maya civilization used chocolate as money," 27 June 2018
Debts in the wir currency, assigned the same value as the Swiss franc, could be paid with sales to any member of the bartering circle: if a baker needed to “purchase” eggs and flour from a farmer, the baker could pay off the debt by “selling” baked goods to another wir member. The farmer, in turn, could use his newly acquired credit to “buy” his own needed items or services. Despite a bank-led campaign to discredit the system, wir stuck. Today, it has more than 60,000 business participants and does the equivalent of about $4.4 billion in annual trade.
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.
Modern barter and trade has evolved considerably to become an effective method of increasing sales, conserving cash, moving inventory, and making use of excess production capacity for businesses around the world. Businesses in a barter earn trade credits (instead of cash) that are deposited into their account. They then have the ability to purchase goods and services from other members utilizing their trade credits – they are not obligated to purchase from who they sold to, and vice-versa. The exchange plays an important role because they provide the record-keeping, brokering expertise and monthly statements to each member. Commercial exchanges make money by charging a commission on each transaction either all on the buy side, all on the sell side, or a combination of both. Transaction fees typically run between 8 and 15%.
In his analysis of barter between coastal and inland villages in the Trobriand Islands, Keith Hart highlighted the difference between highly ceremonial gift exchange between community leaders, and the barter that occurs between individual households. The haggling that takes place between strangers is possible because of the larger temporary political order established by the gift exchanges of leaders. From this he concludes that barter is "an atomized interaction predicated upon the presence of society" (i.e. that social order established by gift exchange), and not typical between complete strangers.