Further to Sir Patrick’s post on the subject.
Permanent Backwardation has not happen yet. Also to watch is GOFO on LBMA.

Prof Antal Fekete has been warning of permanent backwardation in the past 2008.

“December 2, 2008, was a landmark in the saga of the collapsing international
monetary system, yet it did not deserve to be reported in the press: gold went to
backwardation for the first time ever in history. The facts are as follows: on
December 2nd, at the Comex in New York, December gold futures (last delivery:
December 31) were quoted at 1.98% discount to spot, while February gold
futures (last delivery: February 27, 2009) were quoted at 0.14% discount to spot.
(All percentages annualized.) The condition got worse on December 3rd, when
the corresponding figures were 2% and 0.29%. This means that the gold basis
has turned negative, and the condition of backwardation persisted for at least 48
hours. ” ….

“Contango whereby the futures price of gold is quoted at a premium to the spot
price is the normal condition for the gold market, and for a very good reason,
too. “… “For gold, there is no cure. Backwardation in gold is always and
everywhere a monetary phenomenon: it is a reminder of the incurable pathology
of paper money. I”

http://professorfekete.com/articles/AEFRedAlert.pdf