Analytics blog from Avalon Business Systems. To find out more about our analytics offerings and SPSS Modeler please CLICK HERE.

 
alt

AvalonAnalytics.com (Avalon Business Systems, Inc.)

 

      GNP seasonality adjustments appear to be just fine

      Eugen G Tarnow  April 30 2017 09:34:17 AM
      By Eugen Tarnow, Ph.D.
      Avalon Business Systems, Inc.
      http://AvalonAnalytics.com

      The Wall Street Journal questioned the GDP seasonal adjustment methods as the latest quarter came in at a low 0.7% growth and it seemed like the first quarter often comes in low:

      Image:GNP seasonality adjustments appear to be just fine

      An ANOVA test of their hypothesis, however, shows that there is no significant difference between the quarters (p=0.18) so the seasonal adjustment appears to work just fine.  

      (I read the numbers off of the graph as:
      1st quarter 2nd quarter 3rd quarter 4th quarter Year
      3.75
      2.75
      2.45
      2010
      -1.5
      3.25
      0.75
      4.5
      2011
      2.75
      1.875
      0.5
      0.1
      2012
      2.8
      0.8
      3.1
      4
      2013
      -1
      4
      5
      2.2
      2014
      2
      2.65
      2
      0.85
      2015
      0.8
      1.4
      3.5
      2.1
      2016
      0.7
      2017






      ).
      Comments Disabled