If people prepare early, there's no need for panic-buying. Afterall, 10% increase in demand isn't too bad, is it? In addition, some Filipinos already have one-months' worth of groceries in their cabinets.
Others are preparing for six-month disruptions and are now preparing dried food, solar panels, and other survivalist-related provisions. I guess the level of preparedness is a personal choice. Just remember the financial implications of your preparations.