Did GDP Fall Within the 1st Quarter or Not?

Over the past month, I , citing Feldstein, have said that if one looks at available information on monthly GDP, available from estimates of MacroAdvisers, that output declined within the first quarter of the year, even though as standardly reported GDP was higher in QI overall than it had been in the last quarter of 2007.   But, as it turns out, there is some ambiguity to the question.   

The estimates do show GDP falling in February, by a hefty 10.1% anualized.   But the numbers for January and March are up.    To net out the three months, one must split hairs.     The positive numbers for January plus March are just slightly greater in absolute value than February’s negative 0.9 (monthly).   So the net is up?   Not necessarily.

We are trying to figure out the change within the quarter, from beginning to end.   Technically, that means from January 1 to March 30.  But of course even Macroadvisors doesn’t report daily or weekly estimates.   Estimated total real GDP in the month of March was just slightly above total real GDP in the month of December.   So again the net is up?   The most precise measure of the change between January 1 to March 30 is the change between the December-January average and the March-April average.     That is a tiny negative number:   GDP fell by an estimated $28 billion within the first quarter (in year-2000 $).  And April is so flat as to be essentiallz zero.

I think I am sorry I brought the subject up.

It would in any case be a mistake to make much of these numbers.  The reason the Commerce Department’s Bureau of Economic Analysis doesn’t report monthly numbers is that the data are so unreliable, and subject to revision.   For anyone who needs some sort of estimate of monthly GDP, as we do on the NBER Business Cycle Dating Committee as an input into our thinking, this is what we have to go on.    But one sees here yet another illustration as to why the BCDC waits a long time, until all the data are in, before declaring a recession.

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