>who is this hypothetical poor man who's so bad at managing money that an exact total of the amount he's spending will cause him to overspend ?
It is not hypothetical, it is a peculiar - but not so uncommon - man/woman with a limited amount of money in his/her hands (and of course no credit card or similar), the single 50 in the example (but it could be 20 or 100) banknote.
He/she is willing to spend the whole amount of money, but before didn't because he/she was afraid to be seen as having only that given limited amount of money and by making approximate mental calculation tended to undereestimate (or if you prefer preferred to be on the safe side).
With the barcode reader he/she can spend the whole amount of money he/she has available with no risk of appearing (to the cashier, to the people in queue) as "poor".
The poiont is not that with the new system this kind of "poor" people overspend, rather it is that before it underspent.
jaclaz|8 years ago
It is not hypothetical, it is a peculiar - but not so uncommon - man/woman with a limited amount of money in his/her hands (and of course no credit card or similar), the single 50 in the example (but it could be 20 or 100) banknote.
He/she is willing to spend the whole amount of money, but before didn't because he/she was afraid to be seen as having only that given limited amount of money and by making approximate mental calculation tended to undereestimate (or if you prefer preferred to be on the safe side).
With the barcode reader he/she can spend the whole amount of money he/she has available with no risk of appearing (to the cashier, to the people in queue) as "poor".
The poiont is not that with the new system this kind of "poor" people overspend, rather it is that before it underspent.