The "problems" with coins are:
- Inconvenience. Carrying around enough coins to purchase something worthwhile is bulky and heavy. Once a populace gets used to using paper notes over coins, coins generally cease increasing in face value and eventually disappear altogether.
- Counterfeiting. Technology has advanced now to the point where it's relatively easy for organized crime to mass-produce large quantities of high-quality fake coins. Modern high-value coins tend to have lots of anti-counterfeiting widgets, but those are only as good as the public's awareness and use of them. Since the recent upgrades to the British £1 coin, the Australian $2 coin is probably now one of the best value-for-money coins to fake, it's small, relatively easy (no anti-counterfeiting widgets) and in common use. And much of the cost benefits to introducing a new high-value coin are reduced or eliminated, if you have to increase the cost of production by adding anti-counterfeiting devices.
- The invention of polymer notes as a viable alternative to coins. A big argument during the 20th century that drove the re-introduction of high-value coins was the rapid rate of deterioration of a high-circulation paper note. "A $1 note lasts six months, a $1 coin lasts thirty years" was the kind of statistic thrown around. But the invention of polymer notes has given "paper money" a renewed lease on life, because a polymer note lasts almost as long as a metal coin in circulation. Here in Australia in the early 1990s, the Mint was obviously lobbying for introducing a bimetallic $5 coin to replace the paper $5 note - but the polymer $5 note won out. Now, with polymer entrenched, we're never likely going to see a $5 circulation coin. If anything, it would go the other way around: $1 and $2 coins would be replaced with polymer notes, and all coins below $1 eliminated.
But ultimately, the push towards cashlessness will see fewer and fewer new cash types, coin or note, introduced.
- Inconvenience. Carrying around enough coins to purchase something worthwhile is bulky and heavy. Once a populace gets used to using paper notes over coins, coins generally cease increasing in face value and eventually disappear altogether.
- Counterfeiting. Technology has advanced now to the point where it's relatively easy for organized crime to mass-produce large quantities of high-quality fake coins. Modern high-value coins tend to have lots of anti-counterfeiting widgets, but those are only as good as the public's awareness and use of them. Since the recent upgrades to the British £1 coin, the Australian $2 coin is probably now one of the best value-for-money coins to fake, it's small, relatively easy (no anti-counterfeiting widgets) and in common use. And much of the cost benefits to introducing a new high-value coin are reduced or eliminated, if you have to increase the cost of production by adding anti-counterfeiting devices.
- The invention of polymer notes as a viable alternative to coins. A big argument during the 20th century that drove the re-introduction of high-value coins was the rapid rate of deterioration of a high-circulation paper note. "A $1 note lasts six months, a $1 coin lasts thirty years" was the kind of statistic thrown around. But the invention of polymer notes has given "paper money" a renewed lease on life, because a polymer note lasts almost as long as a metal coin in circulation. Here in Australia in the early 1990s, the Mint was obviously lobbying for introducing a bimetallic $5 coin to replace the paper $5 note - but the polymer $5 note won out. Now, with polymer entrenched, we're never likely going to see a $5 circulation coin. If anything, it would go the other way around: $1 and $2 coins would be replaced with polymer notes, and all coins below $1 eliminated.
But ultimately, the push towards cashlessness will see fewer and fewer new cash types, coin or note, introduced.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis