That GDP reading of 4% was complete bullshit. A couple of caveats:
1. I don't know if the numbers can be cooked. People who know say they can't. On the other hand, the numbers have been really wacky ever since Trump fired the BLS commissioner. Could be coincidence. Probably is coincidence. But it's a thing that makes me say hmm.
2. It was 3Q and the data cited here is current. But an economy doesn't go from 4% to zero overnight.
Basically, the issue is that all of the auxiliary signs of economic health, like consumer confidence, employment growth, issues with debt servicing, late or defaulted consumer debt, etc -- all of that points to an economy that is bad. Then this GDP number comes along and it's amazing. Something isn't right.
My theory has been that inflation is being undermeasured. Essentially, the GDP figure is calculated like this: businesses report their production in terms of what they actually pay or receive. Then the total is adjusted downward for inflation. If inflation is understated, then the GDP would be insufficiently deflated and thus would be too high. And it would also explain why everyone is feeling pinched in terms of affordability even though the data looks OK.