When – and why – did people first start using money?

https://theconversation.com/when-and-why-did-people-first-start-using-money-78887?utm_medium=email&utm_campaign=Latest%20from%20The%20Conversation%20for%20June%2025%202017%20-%2076996072%20730am%20send&utm_content=Latest%20from%20The%20Conversation%20for%20June%2025%202017%20-%2076996072%20730am%20send+CID_7474aac3cc8d33f7ab1d4c414d403ebe&utm_source=campaign_monitor_us&utm_term=When%20%20and%20why%20%20did%20people%20first%20start%20using%20money