There was a scene in The Plum in the Golden Vase where Lord Simon and Wu Dajiu discussed military colonies: "Within Jizhou's jurisdiction today, aside from the abandoned reed marshes and harbor passes, there are altogether twenty-seven thousand mu of military farmland. For every qing, the autumn and summer taxes amount to only one tael and eight qian, not even five hundred taels of silver. It is not all collected until year's end, then submitted to Dongping Prefecture and transferred through merchants to provide military grain and horse fodder."
Jiaozi appeared in Sichuan as early as the beginning of the Northern Song dynasty. They were somewhat like bills of exchange, certificates merchants used to withdraw money elsewhere when it was inconvenient to carry large amounts of cash on the road. As Song dynasty commerce developed, Jiaozi issuance and redemption became increasingly common, eventually reaching the point where they were used directly to pay for goods. By Song dynasty measures, one jin equaled sixteen taels. Five hundred taels of silver weighed 31.25 jin. Could Lord Simon and Wu Dajiu even carry that much silver?
Water Margin was written in the early Ming dynasty, while The Plum in the Golden Vase was written in the late Ming dynasty, probably during the Wanli era. Beginning with Hongwu, the Ming dynasty implemented an in-kind economy. Even the Great Ming Paper Notes were printed by the Ministry of Revenue, unlike in the Song dynasty, when the issuance of Jiaozi was entirely entrusted to money houses.
Those factory owners who had Boulton mint tokens for them would not calculate exactly how many coins had been minted. It was much like Song dynasty money houses discovering, while issuing Jiaozi, that they could print a little extra. So long as there was no bank run, there would be