So I set my Spending to 100%. It said I was -48bc in the hole, but the totals didn't add up.
So I clicked back to 99%. My spending dropped to -26bc but all the totals increased.
I fiddled around, and found that, at least on the economy screen, the data displayed is for the PREVIOUS level you chose. So if you click from 98% to 99%, it'll show funding data for 98%. If you click forward to 100%, it'll show data for 99%, but if you click back again, it'll show data for 100%.
Weird.