To be fair, Carter's reign wasn't exactly an economic wonder-time, and I don't think Reagan was influencing the economy that much as governor.
I do think there's a political dimension to the change, but laying the blame at Reagan's feet exclusively seems like simple political point-scoring.
Edit: it's funny seeing this comment getting down-modded. I think I'm significantly more liberal than most people here, but it looks like people are upset that I called out empty partisanship? I fail to see anything particularly inflammatory about what I wrote.