Monday, September 29, 2014

Hopscotch Graphs

The other day I looked at a recent Noahpinion post that used an old David Beckworth graph showing Total Factor Productivity data from John Fernald.

Fernald's TFP (left) looks significantly unlike FRED's TFP (right):

Graph #1: Fernald's TFP (Beckworth)

Graph #2: FRED's TFP

To improve the comparison, I overlaid the one graph on top of the other:

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Graph #3: Beckworth's TFP (blue) Overlaid on FRED TFP (red)

Then I kept looking, and found another TFP graph of Fernald's data from Noah. So now I want to repeat the above layout of graphs, but using Noah's graph in place of Beckworth's:

Graph #4: Fernald's TFP (Noahpinion)

Graph #5: FRED's TFP (again)

Again, the overlay:

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Graph #6: Noah's TFP (blue, green, dingy red) Overlaid on FRED TFP (bright red)
On Graph #3 I adjusted the "overlay" graph up-and-down to get a good fit in the early years. On Graph #6 I adjusted the overlay to get a good fit in the later years. (Noah's graph is taller, and already sits a lot higher than the FRED graph. So I didn't want to move it up more to make the early years align.)

But you can see on Graph #6 that the years from 1980 to maybe 2006 are a good match. The red lines follow the same general trend. Also in the early years, until maybe 1966, the red lines seem to share a trend.

I'm wondering now if maybe the FRED data is calculated in a way similar to Fernald's red line, which shows the TFP for "durables".

One more comparison graph, a straightforward one this time, two FRED series:

Graph #7: Total Factor Productivity (red) and Multifactor Productivity (blue)
Too bad that blue line got such a late start.

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