People can multiply 1, 5, 10, and 25 with zero difficulty. An average person would likely resent being forced to count multiples of a less round number such as 18. For that reason alone, such a change is unlikely to come about.
What the U.S. needs is an 18-cent coin
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Re: What the U.S. needs is an 18-cent coin
#12People can multiply 1, 5, 10, and 25 with zero difficulty. An average person would likely resent being forced to count multiples of a less round number such as 18. For that reason alone, such a change is unlikely to come about.
Re: What the U.S. needs is an 18-cent coin
#13No. What the U.S. needs is NO coins.
(Seriously, does ANYONE use coins anymore? It's either bills or a credit card for me.)
Re: What the U.S. needs is an 18-cent coin
#14An interesting wrinkle to this is that an 18 cent coin would make it much harder to make change with the fewest coins for certain values. How do we make change in everyday life? The simple algorithm everyone knows, even if they don't know what an algorithm is, is to start with the largest coin and move down, taking as many of each as you can. Thus to make change for 72 cents we: take 2 quarters, leaving us with 22 ce…
I don't know why you're saying it isn't NP-complete. For an arbitrary set of coins, it's definitely NP-complete. You could easily reduce 0-1 ILP to it, or subset-sum.
If you don't believe me, believe http://graal.ens-lyon.fr/~abenoit/algo09/coins2.pdf
"Optimally making change—representing a given value with the fewest coins from a set of denominations—is in general NP-hard."
Re: What the U.S. needs is an 18-cent coin
#15The assumption that every possible value from 0 to 99 is equally likely doesn't seem like the best idea. In a country where the cost of items usually ends in .99, .97, or the like, and the sales tax is added after the fact (and usually from 0-10%), is it still the best choice? The post (and cited paper) don't seem to mention this. That said, I don't know where you'd acquire these sorts of statistics.
You seem to be confusing change with sticker prices. Have you ever bought stuff at the supermarket as opposed to, say, shopping for merely single items? You'll find that it is incredibly rare to have the total come out at x dollars and 99 cents or some other marketing sticker price.
Re: What the U.S. needs is an 18-cent coin
#16No. What the U.S. needs is NO coins. (Seriously, does ANYONE use coins anymore? It's either bills or a credit card for me.)
Yes, I still use coins. They're very handy for vending machines, parking meters, highway tolls, stupid magic tricks, decision making, purchasing one taco at taco bell, carnival food, making wishes, receiving change, and so on. I don't think coins will go away as long as paper currency remains, unless we start printing bills worth less than a whole dollar, or we become so rich that we don't concern ourselves with values less than one dollar.
Re: What the U.S. needs is an 18-cent coin
#17No. What the U.S. needs is NO coins. (Seriously, does ANYONE use coins anymore? It's either bills or a credit card for me.)
Yes, I still use coins. They're very handy for vending machines, parking meters, highway tolls, stupid magic tricks, decision making, purchasing one taco at taco bell, carnival food, making wishes, receiving change, and so on. I don't think coins will go away as long as paper currency remains, unless we start printing bills worth less than a whole dollar, or we become so rich that we don't concern ourselves with valu…
exactly. I've been in singapore the past couple of weeks and they have a S$ 1 coin and it's been awesome.
They also have http://en.wikipedia.org/wiki/Polymer_banknote which is great in terms of durability.
Re: What the U.S. needs is an 18-cent coin
#18The assumption that every possible value from 0 to 99 is equally likely doesn't seem like the best idea. In a country where the cost of items usually ends in .99, .97, or the like, and the sales tax is added after the fact (and usually from 0-10%), is it still the best choice? The post (and cited paper) don't seem to mention this. That said, I don't know where you'd acquire these sorts of statistics.
Credit card companies would know, but probably not publish.
Re: What the U.S. needs is an 18-cent coin
#19> Shallit assumed that every amount of change between 0 and 99 cents is equally likely.
Fail. He could at least have blagged some transaction data from a retailer that actually does a bunch of small cash transactions. Just getting copies of the receipt roles from his local bodega would be better than this.
Re: What the U.S. needs is an 18-cent coin
#20Or, they could get rid of every coin smaller than a quarter. Assuming every amount of change less than a dollar is equally likely, the average number of coins needed to make change now becomes 1.5 - and it's not like anybody really uses anything less than a quarter for anything other than coinstar anyways