Their economies were largely focused on agricultural and craft related commodities. To document such transactions, record keeping tools and practices had been established; however, the tools utilized by each civilization differed. A monetary currency system did not appear to exist within these complex economies. The complex economies of each civilization were largely driven by middle class people; though, Maya trade was likely overseen by a dynastic ruler.
Harappan Economics
Harappan farmers and artisans produced valuable trade commodities such as food, jewelry (i.e., metal beads), ceramic pots, metal figurines, and cotton textiles. Seal making was especially important to Harappan economics. This practice involved engraving pieces of wet clay to document a trade transaction (similar to a modern day receipt). In addition, the Harappan weight system likely played a role in regulating transactions. Whereas land based was a shared transportation method between civilizations, the Harappan civilization used sailing vessels to internationally import and export large sums of commodities.
Maya