Final answer:
Under the Song Dynasty, the switch to using money for tax payments led to increased economic development and prosperity for farmers, though it made difficult years more challenging. The policy supported a move away from subsistence farming to a more diverse and resilient economic structure that increased purchasing power for farmers.
Step-by-step explanation:
Under the Song Dynasty, farmers were allowed to use money instead of crops to pay their taxes; this policy had significant economic impacts. The Tang Dynasty, unlike the Song, had collected taxes in grain and cloth and disdained commercial taxes, relying more on territorial expansion. In contrast, the Song Dynasty focused on internal economic development, favoring monetary taxes and commercial activities. This approach allowed for agricultural innovations and the creation of surplus, which led to urbanization and increased purchasing power for farmers. The use of money for taxes made transactions more efficient, but it could be difficult for peasants in years of poor yields since they were required to pay regardless of their profits. Consequently, this system contributed to widespread prosperity among farmers in good years, but could be crippling in bad years when they lacked the cash to fulfill their tax obligations.