"To show you the scope of the phenomenon, we pull out a copy of The New York Times from October 19th, 1896. There, it is recorded in black and white that the average wheat price was about $1 a bushel – in gold – during the previous 20 years. An ounce of gold would buy you 20 bushels of wheat."

"Today, you can buy a bushel of wheat for about $12 which means, an ounce of gold will buy about 75 bushels of wheat. In terms of real money – gold – the price of wheat has gone down for more than 100 years. However fast farmers have added to the world’s wheat output, in other words, central banks have outdone them, planting far more acreage in paper money."

I think he is saying 1 oz. gold costs $20. in 1896.& that 1 oz. also wud buy 20 b. of wheat at $1. each.  Suppose you took the same 1 oz. gold & sold it for $20. & invested it in bonds, mortgages or stocks & averaged a return of 5% over the 102 years to present day.  The money should double about every 14.4 years so your original $20. should grow to about $2,600. which in turn will buy about 216 B. of wheat today as compared to 75 bushels if you used your gold.  Wheat is much more efficiently produced today & is not a good illustration of decline in purchasing power.  Look at housing up maybe 500 times!!