I know you all want to jump in and offer your suggestions. Do not, however, be too scathing. Seriously, the clue train shows signs of having made an unscheduled stop at the Guardian station. The article mentions, albeit in a hurried way and sandwiched between irrelevancies, price controls as a possible explanation for the mystery. And this is downright subversive:
For Oliveros, an additional cause for the shortage of basic food staples is the decrease in agricultural production resulting from seized companies and land expropriations.
From the way that is phrased one could almost think that a decrease in agricultural production was a result of seized companies and land expropriation. I am beginning to wonder if the “No one can explain it” title was selected by either the writer or the mole among the Guardian‘s sub editors in order to call forth the responses it did get.