Walker Asset Management of Connecticut has developed a system to allow fast
food restaurants to adjust the price of food according to its age.
Under the system, a countdown begins as soon as food is cooked, so each
burger or pie has an expiry time. A coloured indicator for each item changes
from green for fresh to red for old and finally bleeps a warning when it’s time
to throw the food away (WO 99/10794). As the food ages, it can be bought for
ever more tempting prices.
