Did Thanos' calculations account for aftermath effects?

No...

Nor I suspect does he care. His, let's face it delusional, plan is that destroying half the life in the universe will, essentially, cure all ills.

Recall that in his mind he is saving the whole universe from eventual extinction... saving half is better than all of them dying!!

There's a similar / related question on SF&F: What is Thanos's motivation for his action?

Here's a quote from one answer.

..his plan in Avengers: Infinity War. It fails to solve the problem in exactly the same way, and it likewise ignores many obvious resources and alternative solutions that could solve the problem in a non-bonkers way.

It’s a bit like the classic proverb that, when you only have a hammer, you see every problem as a nail. Except in this case, Thanos is so obsessed with hammering a nail that he went out and got an infinitely powerful multi-tool and then used it as a hammer.

^{Bradd Szonye}

With all six Stones, I could simply snap my fingers. They would all cease to exist. I call that mercy.

And then what?

I finally rest. And watch the sun rise on a grateful universe. The hardest choices require the strongest wills

There's is no indication that Thanos has considered the aftermath or even the fact that populations would, again, grow exponentially afterwards... meaning that he'd have to do it all over again (assuming he can).

His plan is to snap his fingers, kill half the life in the universe and then sit back and bask in the glow of the gratitude of the remaining population.

He's crazy....and crazy doesn't consider consequences.

The stated goal of wiping out half the universe, and the idea of perfect balance seem to have only been ideals. Ones that Thanos was not too particular about achieving.

There are two scenes in the movie that support this line of thinking. During the first flashback with young Gamora, we see Thanos invade her planet. There are many corpses already on the ground when Thanos divides the remaining population in half and executes them. This would mean that those that remain alive already make up less than half of the original population, since an unknown number have perished in combat.

This is further reinforced by the start of the movie. When Thor and his people encounter Thanos, their population is already reduced due to the events of Thor: Ragnarok. And yet we see Thanos purge everyone who ended up on the ship fragment with Thor. Regardless of whether we assume that some Asgardians remained alive in another fragment of the ship, these actions once again skew the math for achieving "perfect balance".

By using the gauntlet to precisely delete half of the population in the galaxy, he is probably closer than ever before to achieving the perfect balance he talks about. And based on previous examples of his actions, that is likely good enough for his tastes.