1.08 income changes while GDP maxed

To be clear, I don’t necessarily thing that’s a bug, but my income suddenly fluctuates by a bit more than a billion $ (US) even as income is stably maxed. Is this a result of balance changes?

If so I think I like it, although it’d be even better if GDP didn’t appear maxed.

Ministers have loyalty, experience and effectiveness.
Stuff, that changes it, will change policy cost and income.

Also taxes change income depending on various factors, for example upping tax will decrease consumption (alcohol, tobacco, drugs and cars).
There is laffer’s curve, and some taxes will decrease GDP.

Nope, this is late game, my ministers love me, with literally nothing changing at all, efficiencies are 111% for income, 107% for expenditure constantly, I have no debt (in fact I have a $1.99T surplus that doesn’t generate any interest) and it’s clearly fluctuating with the Global GDP and nothing else. I also am not adjusting the tax rate between turns. The only thing that does change is decisions/events which, to my knowledge don’t have a direct impact on income if they don’t affect GDP beyond the maxed out threshold. And certainly not a cyclic one.

income is all tax, and the tax collected will depend both on the ministerial effectiveness, and any other variables feeding into tax. For example, if some of your income is car tax, and the car usage goes up due to some combination of factors, then car tax income will go up.
Dont forget all policies have a button that lets you see the cost or income history in a chart, so it might be possible to see the variance there?

I already had no motorists for ages, heh

Every policy was stabilized so I don’t see how there could have been a change that just happens to go up and down exactly with Global GDP while GDP itself is precisely maxed.
But I probably should just check all the histories to figure it out…