A balance must be struck between the obligations of the producer and the obligations of the procurer for the child's safe consumption of the product. The calculus of negligence is a legal approach, in the spirit of procurement efficiency, that attempts to strike that balance on economic grounds. This is most easily understood in terms of insurance liability. Should a car driver have a duty of care towards unlit cyclists at night or should the cyclist have a duty of care to properly illuminate his bicycle at night? The costs of bicycle illumination are considerably less than the cost of driving with a duty of care to unlit cyclists.