Hoarding is a common problem before and during an emergency. It is not uncommon to see some form of rationing. Examples can be as simple as the number of MRE’s and bottled water handed out per person. A more forceful example is the gasoline rationing that is taking place after hurricane Sandy.
Gasoline was hard to get so when it was available people were buying all they could afford and store. This just helped to make gasoline less available. The rationing plan works by “Drivers with license plates ending in an even number will be able to buy gas on even-numbered days, and those with plates ending in an odd number can make gas purchases on odd-numbered days.” Using the number on the license plate seems to be standard practice for gas rationing in America. So before the next emergency if you have two or more cars you may wish to make sure that some have plates ending in a even number and some have plates ending in a odd number.
Also, remember to prepare well in advance of the risk. For those who wait to purchase what they need are likely to be the ones who go without. Think about conserving gas by preparing carpooling plans before an emergency. If you are a business maybe organize some van pools to get employees to work and needed supplies back to employees homes before the event.