Cows keep producing milk, but that's not much good unless you live near the cows.

Factories stop making iPods since people don't go to work if they know they won't get paid. Likewise, the truck drivers won't keep bringing food to the supermarket. Which might not matter anyway if your bank has collapsed and you don't have any cash.

So after your food has run out, and you know your neighbour has food but doesn't want to share it with you, what do you think happens next?