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.
In Spain (particularly the Catalonia region) there is a growing number of exchange markets. These barter markets or swap meets work without money. Participants bring things they do not need and exchange them for the unwanted goods of another participant. Swapping among three parties often helps satisfy tastes when trying to get around the rule that money is not allowed.
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.
Since the latest series of worldwide economic meltdowns, people have bartered in growing numbers. Last year, the 100 members of the International Reciprocal Trade Association, a network of barter and trade exchanges, facilitated the bartering of billions of dollars’ worth of goods and services around the world. (The IRTA uses its own barter currency called Universal Currency.) In some areas of Greece, bartering has become as second nature as paying for things with cash—there’s even a new barter-style currency called the TEM, accrued through offering goods and services via a vast online network and regular open-air market days. Spain’s time bank system, in which people exchange hours of labour instead of units of currency, has grown exponentially as a result of the country’s crippled economy.