Here in Finland we have a strong recommendation from the government that everyone should have enough supplies to last 72 hours. There's guides available on what to have, how to do it and what to take into consideration. It's far easier for everyone if something big happens (storm, flood, war, problems with electricity/water grid...) to the rescue workers if the whole population isn't in an emergency after few hours. I think that's becoming more and more important globally as the climate changes and global environment gets more and more unstable.