I think that at at a 21% tax rate, he's rightfully more concerned about profits, which will be post tax in a Roth. Assume he's making 10% a year in his money, a Roth is a no brainer lechaora

Let me start by getting this off my chest: Why is this in the CC board?

Now that we've cleared that, let's just establish that if everything remains equal (tax rates, tax bracket, growth rates) there shouldn't be any nominal mathematical difference between a ROTH and a Traditional (I won't say 401k, because there are other features other than deductibility that could come into play, and if employer offers it there could also be a ROTH 401k).

Let's use $1,000 and a 20% rate as an example. Using your hypothetical 10% annual growth rate, and assuming it's there for 38 years, making the final balance 34x the original deposit.

If we took $1,000 pre-tax it would grow to $34,000. And after being taxed at 20% we get $27,200.

If we first paid $200 in taxes, and only invested $800, the final balance would be... $27,200 which would be tax free.

If there's an employer match, that is an absolute no-brainer to maximize that match (I've seen very lucrative matches for educators).