Speculations on gold speculation (1969)
This 1969 paper offers an insight into the discussions around what the correct level for the gold price might have been before the closure of the gold window in 1971. It offers information on the supply and demand for gold at that period.
He concludes that the 1969 gold price of $35 would not hold without government intervention and would fall significantly if governments sold their reserves. In his opinion it is only official links that allowed gold to be seen as a safe asset at this time. The below chart shows the evolution of the gold price from 1968 to 1975.
Reference: Speculations on Gold Speculation. Fritz Machlup. The American Economic Review, Vol. 59, No. 2, Papers and Proceedings of the Eighty-first Annual Meeting of the American Economic Association (May, 1969), pp. 332-343.