Why it matters: Consumers used less cash in 2020. That along with a trend toward digital transactions in the smaller-dollar realm — the last stronghold of the legal cash economy — implies the cash in circulation is largely being used for under-the-table or illicit activities. This could strengthen the rationale for governments to develop their own digital currencies, which would be trackable and taxable. What's happening: More consumers are going digital for obvious reasons — the convenience, the safety of not carrying around wads of cash, and after COVID, because of sanitary concerns, says Jody Jonsson, portfolio manager at Capital Group. And while the entirety of cash payments is impossible to track, we can see that digital payments have grown faster than overall consumption over the past decade, Kenneth Rogoff, professor of economics at Harvard, tells Axios.