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[citation needed]. 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.[3]
Since the 1830s, direct barter in western market economies has been aided by exchanges which frequently utilize alternative currencies based on the labor theory of value, and designed to prevent profit taking by intermediators. Examples include the Owenite socialists, the Cincinnati Time store, and more recently Ithaca HOURS (Time banking) and the LETS system. 

Bartering allows individuals to trade items that they already have but are not using for items that they need while keeping their cash on hand for expenses that cannot be paid through bartering such as a mortgage, medical bills and utilities. Bartering can also have a psychological benefit because it can create a deeper personal relationship between trading partners than a typical monetized transaction. Bartering can also help people build professional networks and market their businesses.
In Spain (particularly the Catalonia region) there is a growing number of exchange markets.[24] 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.[25]
People often require some encouragement to give bartering a shot. Debbie Lombardi, president and founder of Barter Business Unlimited, a Connecticut-based exchange network, says that despite her company’s track record and 4,000-plus registered members, she still regularly encounters resistance and confusion from prospective customers. “Nobody comes to me and says, ‘I’ve always wanted to try bartering,’ ” she admits. “It’s more like, ‘I don’t get it. Is this some kind of scam?’”

“Economic theory has always got to be historically bounded,” Beggs says. “I think it’s a mistake to think you’ll find the workings of modern money by going back to the origins of money.” He does point out that, while barter may not have been widespread, it’s possible that it happened somewhere and led to money, just given how much is unknown about such a large period of time.