thumb|A Ming dynasty banknote The economic growth was supported by the government's expansion of precious metal mining, particularly copper and silver, in southern China and Jiaozhi. The government also increased the emission of paper money (banknotes, baochao). Revenues from silver mining, which previously accounted for only 30% of output, rose significantly from 1.1 tons in 1390 to over 10 tons in 1409, and remained at this level for the rest of the Yongle Emperor's reign. The government also produced coins from the mined copper, which were stored in state treasuries and given as gifts to foreign embassies, but these coins continued to circulate on the domestic market alongside the baochao, in contrast to the Xuande and Zhengtong eras (1425-1447) when they were removed from circulation under government pressure.
thumb|A Ming dynasty banknote The economic growth was supported by the government's expansion of precious metal mining, particularly copper and silver, in southern China and Jiaozhi The government also increased the emission of paper money (banknotes, baochao). Revenues from silver mining, which previously accounted for only 30% of output, rose significantly from 1.1 tons in 1390 to over 10 tons in 1409, and remained at this level for the rest of the Yongle Emperor's reign. The government also produced coins from the mined copper, which were stored in state treasuries and given as gifts to foreign embassies, but these coins continued to circulate on the domestic market alongside the baochao, in contrast to the Xuande and Zhengtong eras (1425-1447) when they were removed from circulation under government pressure.