Friday, September 21, 2007

Trend Line Disclaimer

I just want to point out that when you see trend lines in any charts I make please don't read much into them.

The only thing that can predict the future is a time machine. I don't have one of those. Heck, I don't even have a crystal ball. My trend lines are simply there to give you a "feel" for one possibility out of many (an infinite number).

If the data seems to be following a straight line then I pick a straight line to show it. If the data is wobbling all over the place then I simply find a similar wobbly line to show it. Please don't confuse cause and effect or come to believe in the wobbly line I chose just because it seems to match the data. I like to get a "feel" for the data, much like an artist might. It doesn't have much intrinsic value though.

Excel Polynomial Trendline Equation doesn't accurately predict future data

If finding a suitable wobbly line that matched past data was all it took to predict the future, I could tell you what the weather will be like 10 years from now. Not going to happen, lol.

I would also refer you to the 10 Year Treasury Yield post. Note that I have two charts of the data with two different trend lines and the predictions into the future are exact opposites. Clearly one of the two must be wrong and most likely neither are right. It is up to the person reading the charts to attempt to make sense of it (not that we are any better at predicting the future than Excel is when it comes right down to it).

This was inspired by a comment left by jus me who pointed out the risks in my trend lines. Agreed!


Anonymous said...

Heck, I don't even have a crystal ball.

I think China makes those don't they, might not be any more accurate then your trend line but I bet you can buy one somewhere. If not maybe there is a business opportunity with the proper discloses of course and one might even be able to sneak in some type of anti law suit clause in the fine print that makes anyone who tries to sue you instantly responsible for your future financial obligations. Dumber thing have happened.


Stagflationary Mark said...

I think we could really cut costs if we opted for a crystal mood ring. As an added bonus just think how small the fine print would be (assuming it wasn't directly under the crystal mood lens).

Unfortunately, I wouldn't want to compete with Archie McPhee's Excuse Ball. If people have to choose one of the two in the not too distant future, we might lose out big time.

Anonymous said...

Mark I think Archie has the superior business plan that's for sure. Damn.

Stagflationary Mark said...

Hey, based on the non-scientific poll here perhaps there's money to be made in:

Magic Eight Ball of Doom

The future is grim.

You aren't being told the truth.

You didn't buy nearly enough canned goods.