Good general rule. However, if you are doing some kind of general economic modeling, with estimated parameters all around, not claiming to represent anyone's ac

Good general rule. However, if you are doing some kind of general economic modeling, with estimated parameters all around, not claiming to represent anyone's accounts or ledgers, I suspect an exception applies. "When you are dealing with things that are measured" ... or wild-ass guesses. And I doubt demographers and actuaries are all using integer arithmetic for projecting technically integer-count human-life outcomes. Calculating taxes: Be careful and conventional, as you say.