Unique Characteristics and Synchonicity of Currencies in Medieval and Early Modern East Asia and their Implications in the Theory of Money

铜钱起源于中国，其面额很小，在中世纪的日本占据了货币交易的主导地位。由于小面额货币的收集和运输需要很大的成本，一个区域经济体倾向于混合多种货币，这些货币的面额可以完全涵盖所有交易规模。对一种货币的接受不仅取决于当局的内在价值或外在强制，而且取决于它是否能适应区域市场所需的各种货币。

Copper cashes originated from China whose denominations were small had dominated monetary transactions through medieval Japan. As collection and transportation of small denomination currencies needed a large cost, a regional economy tended to assort plural currencies whose denominations could fully cover all size of transactions. Acceptance of a currency depended not only on intrinsic value or extrinsic enforcement by authority but on whether it could fit in the assortment of currencies which regional market demanded.