substitute for certain written records. In bigger operations there are human "memorizers" who serve as arbiters in case of dispute. The Hawala system requires unbounded trust. Hawaladars are often members of the same family, village, clan, or ethnic group. It is a system older than the West. The ancient Chinese had their own "Hawala" - "fei qian" (or "flying money"). Arab traders used it to avoid being robbed on the Silk Road. Cheating is punished by effective ex- communication and "loss of honour" - the equivalent of an economic death sentence. Physical violence is rarer but not unheard of. Violence sometimes also erupts between money recipients and robbers who are after the huge quantities of physical cash sloshing about the system. But these, too, are rare events, as rare as bank robberies. One result of this effective social regulation is that commodity traders in Asia shift hundreds of millions of US dollars per trade based solely on trust and the verbal commitment of their counterparts. Hawala arrangements are used to avoid customs duties, consumption taxes, and other trade-related levies. Suppliers provide importers with lower prices on their invoices, and get paid the difference via Hawala. Legitimate transactions and tax evasion constitute the bulk of Hawala operations. Modern Hawala networks emerged in the 1960's and 1970's to circumvent official bans on gold imports in Southeast Asia and to facilitate the transfer of hard earned wages of expatriates to their families ("home remittances") and their conversion at rates more favourable (often double) than the government's.