A 20-lb bag of rice for $60??? And she bought six of them?
That must be some fancy rice. Normally a **50-lb** bag of jasmine rice goes for around $20. My wife is Chinese, and we go through a lot of it. Usually get it at Costco.
My guess is, you're in Silicon Valley where we are hearing rumors of short supplies of rice, and she hit the panic button. And she ran into an opportunistic distributor who took advantage of her.
I've heard stories about U.S. cropland (and other places) switching from whatever they used to grow, to corn to fill the government-mandated demand for ethanol for fuel. Farmers who used to grow wheat or rice or whatever, are now growing corn to get all those nice government subsidies. And so not as much wheat, rice etc. is being grown.
But I doubt the effect is that big this suddenly, that there are now rice shortages. More likely some distributor who used to get his shipments of rice from XXX Corporation, was told that XXX is shipping less of it, and he didn't switch his order to some other company fast enough, so he shorted a few of the stores he was distributing it to. They ran out, but they'll be back in full stock in a week or three. That's my guess, anyway - a temporary hiccup, but a few people immediately assumed the sky is falling. Such as your neighbor.
Still, the long-term outlook deserves to be examined. Might domestic rice production start going down? And, how much rice does the US normally import from other countries? Mexico grows a lot, and obviously the Asian countries do. Are they affected by this govt-created demand for ethanol, enough that they,too, are cutting rice production? I don't know. But it might be interesting to find out.
Is your neighbor nutz? Short answer: Yes, a little. She might start feeling silly when the usual stores fill their shelves and go back to normal prices pretty soon.
Can I prove it? No. But if the rice supply were being totally cut off, long-term (the only circumstance that would justify her panic buying like that), you wouldn't have to guess there was a problem. There would be massive riots at every store that used to sell rice, and not just Asian people rioting. Seen any such riots?
