The proliferation of the GDPNow report has turned into a real test of economists.

It’s a semi-useful indicator but really only in the couple weeks before the advance US release, when much of the data has been released. Instead, people quote it throughout the quarter at times when it’s based on vague assumptions and models that are volatile.

Moreover, the US government shutdown rendered the current version virtually obsolete and that won’t improve until we catch up on the data in Q1.

Now I understand why politicians love to quote this number when it’s running hot like it is now, but if you’re in markets, you need to know better. If the Atlanta Fed was serious, it would have stopped publishing this report and pulled its estimates.

All that said, the latest number is down to 3.8% from 3.9%.