Actually that would break so many things (the cent as the smallest unit in law and in custom where that is currently the case) that governments may by preference issue a whole new currency instead of stir that pot.
> https://www.law.cornell.edu/uscode/text/31/5101 says "United States money is expressed in dollars, dimes or tenths, cents or hundreths,[1] and mills or thousandths. A dime is a tenth of a dollar, a cent is a hundredth of a dollar, and a mill is a thousandth of a dollar."
> [1] So in original. Probably should be “hundredths,”.
About the only time you see values given in mills is with gas prices, like $4.999/gal, though often denoted as tenths of a cent. It's also indirectly used in property taxes.
This year on our local ballot there is a tax levy to approve an increase to the property tax by 5 mills per 100,000 dollars of assessed property value. Allegedly allowing them to raise a few million over the next 10 years to pay off an addition to the school.
Fiat currency can go to -4 i think, crypto currency going to -18. And that's whole units like cents
P.S. crypto things are using uint256 internally, and this type don't exist in most languages. Using int64 can work out, sometimes, and will usually break soon enough
In a situation like that I think it would be better to have the system not work until it’s fixed than to potentially lose precision and work with untested inputs
I believe that economists generally think that a small amount of inflation is good for the economy, and that deflation is bad (because it leads to reductions in spending and investment, potentially causing a vicious circle). It's also relatively easy to counteract - just print more. In order for hyperdeflation to occur you'd need a currency where the issuing body didn't believe deflation was bad, or didn't care.
It's not really symmetric. It's not hard to imagine a situation where everyone stops believing something (a currency) is not worth anything anymore. But why would somebody believe that nothing except currency is not worth anything?
I think you could easily convert every stored value to the new unit of measure by multiplying by an appropriate factor. In your example that would mean multiplying all the old values by 10. But when you're designing such software, you could also be conservative and use a smaller unit than cents (which probably many financial sw already do, as you already have things considering fractions of cents like gasoline prices).
Different currencies already have different rules. Any good accounting software isn't going to assume US cents. Update your currency table to include a version of USD in increments of $0.001. Update the amounts on a need-be basis. ( Multiply by 10 and change the currency type)
Division. 1/x is a common operation in finance (particularly in trading), and you'll get all sorts of trouble if you try to express everything in cents.
So, you'll need subpenny fractions (e.g. 8 decimal points), or BigDecimal, or decimal-normalized floats.
