I made no ‘claim’. I told you the method used.
You said: “Personal property is a WEALTH concept. There is no accurate way of estimating income from wealth as anyone who has studied any economics knows.”
Tell that to Parker, Fogel, and Engerman.
So this brings us back to the per capita income data, derived from the census.
And not my calculation.
The per capita income of free populations in 1860 as compiled by the United States Census was the following:
........................South..............North
...........................$150................$142
Not is that not income but it only counts part of the population. It is worthless. “per capita” means total population. 128 to 103 South down by 20% even by the wealth measure.
You posted those numbers with the hope they supported your argument. They do not and proved it wrong. I am telling you as I am sure the authors have been told by statisticians/economists that they do not measure income.