Q:

Does lowering taxes really stimulate city growth?

I understand that a tax rate that's too high can discourage district types, and even cause companies to pack up and leave, but does lowering taxes below the starting level make a difference in regards to growth?
I'm working on the Trains! scenario where I need to race to 12k population in 150 weeks.  I heard a rumor that lowering taxes can help entice people to move in, but so far I haven't seen a substantial difference.
In my setup, I have plenty of zoned high residential, commercial, and industrial zones available, so much that there's little demand for anything.  All my taxes are at 10%.
My first attempt I didn't touch taxes at all.  The last ten weeks of the map I went from 10,627 to 11,532 population, for a gain of 905.
My second attempt, I rewound to the 140 week mark and tried setting the tax for high residential to 2% and used the high residential tax break district policy to (presumably) drop it to 0%.  I ended up with 11,619 people, for a gain of 992, or 87 more than the full tax trial.
My third attempt, I rewound to the 130 week mark and did the same: high residential taxes to 2%, high residential tax break to try and drop it to 0%, all unoccupied low residential rezoned to high residential.  I saw growth from 9,574 to 11,651, ending up with about 32 more people with 0% taxes for 20 weeks than when running 0% taxes for 10 weeks.
So it seems like there might be a slight difference, but the difference between the 10 and 20 week experiments is small enough that I could chalk it up to randomness or slightly different placement of parks/services/roads.
Does a tax break provide a growth benefit?  If so, how much?  And are there diminishing returns?

A:

So far in my games I haven't found any noticeable difference with lowering taxes below the default.  The main driver of residential growth seems to be the availability of jobs, with high unemployment leading to reduced residential demand and underemployment leading to higher demand.  There's also a limit to the number of people that can migrate in at a time, so if there was once some benefit, we can't see it because of this migration limit.
Note that tax rates above 12% will cause citizens to complain and eventually move out, but any difference between 12% and 1% seems to be negligible enough to not matter and is outweighed by other factors.
Thus, it seems harmless to just set all taxes to 12% as soon as you unlock the tax milestone.

