And merchants may not mind, either. Yes, they may have to incur more fees with centralized cashless systems (debit swipe fees alone were estimated at $16.2 billion in 2009), but a 2004 joint study from AEI and the Brookings Institute estimates that a nation would save about one percent of GDP shifting from cash to cashless. In the U.S., that would be in the neighborhood of $146 billion a year, based on the 2010 GDP.
The savings would be realized in costs required to handle currency: physically transporting it around alone costs a lot for merchants, once you take into account staffing costs and insurance fees for moving cash. Without cash, stores could shift to self-service checkout lanes, thus reducing personnel costs.
The numbers in the 2004 study seem a bit exaggerated.
I estimate the cost of handling the logistics of cash in France amount to 500 million € per year.
I imagine the US figure could be in the $5 billion range but how do they come up with $146 billion ?