Exchange - Aikae

…According to research by Niida Sho, the ancient Chinese book “Shigaku Shinan” states, “Trade is the exchange of goods and goods, which is called trade, and mutual exchange is called exchange.” It was introduced to Japan and used from the early ancient period, and was also called aikae. For example, in a letter sent to the governor of Sagami Province on January 23, 754, by the envoy from Todaiji Temple, wishing to exchange one cho of temple land in Sagami Province for a residence in the same province, it states, “I hope that we can work out the circumstances of both sides and obtain mutual exchange.” …

*Some of the terminology explanations that mention "phase change" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…仁井田陞の研究によると，中国古代の書《吏学指南》に，〈貿易　以物易財曰貿　互相博換曰易〉とある。日本に伝わり古代前期から使用され，相替（あいかえ）ともいわれた。用例としては，造東大寺使が相模国にある寺地1町と同国の調邸との交換を希望し，天平勝宝6年(754)1月23日付で相模国司に送った牒に〈願くば彼此の便を計り，相博を得んと欲す〉とある。…

※「相替」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報