## Monday, July 13, 2015

### What Seasonally-Adjusted U.S. Economic Data Needs Most...

...is non-adjustment. This is not a minor issue: there's not even an unadjusted U.S. GDP!

Seasonal adjustment is sometimes desirable, but sometimes not. Sometimes it's done poorly, sometimes it's better done with extra care and transparency by the researcher, etc. And the restrictions implied by economic theory generally hold across all frequencies, not just non-seasonal frequencies. There are many, many issues. (See, for example, the discussion in Hansen and Sargent (1993) and the references there.)