Friday, November 16, 2007

The X-12-ARIMA Seasonal Adjustment Program

The Census Bureau provides a tool which creates seasonally adjusted data.

The X-12-ARIMA Seasonal Adjustment Program

It spits out an impressive amount of information when you run it (page after page of data analysis).



The thick black line was my attempt to seasonally adjust the data. The tool generated the thin purple line (using the default settings). I know just enough about the tool to be dangerous now, lol. I will say I trust the seasonal adjustments from the government more than I once did. I also trust the tool enough to value its data more than my relatively crude attempt and will be using it in the future.

You can see the thinking behind my seasonally adjusted attempt in the link below.

See Also:
Another Look at Cargo Traffic

Source Data:
Port of Los Angeles: Statistics

2 comments:

  1. If, as a Asian production planner, you had projected US imports (specifically into LA) based on 2005-2006, you would have expected 420,000 TEU's at end of 2007, Instead the number appears to be 360,000 TEU's, 17% less.

    Perhaps you were cleverer, and more conservative than that, but it's not likely that you would have anticipated that big of a drop.

    In short, if as commenters on CR imply the Chinese production model depends on growth, there should already be problems showing up there.

    Do you know of any?

    ReplyDelete
  2. picosec,

    I keep looking but so far no luck.

    I'll be posting some charts showing Long Beach traffic shortly.

    ReplyDelete