I think they forgot a comma. "Economically, gifted students are likely to have an outsized impact"

If there's a sensible read of someone's comment it's preferable to use that interpretation. "Economically gifted" makes no sense in the context of the discussion.

The OP was saying your tax dollars are likely to get a good return by fostering the progress of gifted students.

Seeing as a lot of people are pointing out the omission of a comma, what would you say to a person who wasn't economically fortunate but ended up in a GT program? Would that justify the tax expense?

I think there's a comma missing there. Plenty of gifted students in my son's school qualify for the free lunch program.

Or you can realize that GP left out a comma, or with a slight rephrasing:

  Economically speaking, gifted students ...

I think Retric meant Economically, gifted students...