Ok, good. Sanity check 
I think it should be -(Ft - F0)/S0. F/S=1+idom/1+ilocal If there is difference in interest rates ratio then the basis has changed. Therefor I think -(Ft - F0) should be compared to initial spot price
Ok, good. Sanity check
I think it should be -(Ft - F0)/S0. F/S=1+idom/1+ilocal If there is difference in interest rates ratio then the basis has changed. Therefor I think -(Ft - F0) should be compared to initial spot price