Not sure if anybody mentioned this before, but is it possible the economy is influenced by total available planetary spots?
So for example a planet has 6 spots, you build 1 refinery -> 1/6 isn't close enough to 0.5 so it gets ignored (some rounding error), resulting in 1.00 colony economy.
And then for example a planet has 2 spots, you build 1 refinery -> 1/2 = 0.5, resulting in 0.5 refinery economy
It's a stretch, but might explain why different people get different results when building the same hubs.
So for example a planet has 6 spots, you build 1 refinery -> 1/6 isn't close enough to 0.5 so it gets ignored (some rounding error), resulting in 1.00 colony economy.
And then for example a planet has 2 spots, you build 1 refinery -> 1/2 = 0.5, resulting in 0.5 refinery economy
It's a stretch, but might explain why different people get different results when building the same hubs.