Saturday, December 24, 2011

RGDP: Annual Change and a 21-Year Moving Average

I was impressed by Jazzbumpa's 21-year moving average in his Disturbing Look at GDP Growth. So I decided to extend the 21-year M.A. as far out in time as I could.

For the U.S., the annual "Real GDP" numbers from Measuringworth run from 1790 to 2010. I figured "percent change from year ago" from that, so my first number is for 1791. And I figured a 21-year average and plotted it at the last year of the period, so my first M.A. comes in at 1811. So, I got a hundred numbers to look at.

Graph #1

Sorry about the scrollbar. Without it, Google Docs was just ignoring everything after the mid-1950s. Information overload, I guess.

1 comment:

Jazzbumpa said...

Just a caveat on the historical numbers. Anything prior to about 1929 is not primary data. It's an estimate cobbled together from extrapolations and assumptions. The further back you go, the more vague it all becomes.

Merry Christmas!