On Tue, 30 Dec 2014 11:28:11 -0800, mike wrote:

On 12/30/2014 7:03 AM, Ed Huntress wrote:

I just can't project that far ahead.

It's not rocket science. It's simple math.
The first order approximation to ANYTHING is to assume
the current trend continues at the same slope.
If you don't like the trend, saying you can't predict is not
helpful.

Decide first which trend you're going to follow. Ir it's changes in
GDP growth rates, in 40 years Americans will all be rich and the
Chinese won't have a pot to pee in.

'Not likely. It is not simple math. It's immensely complex.
I'm gonna disagree. The math is simple.
The hard part is deciding which crystal ball to use for the inputs.

Picking a metric and the five top things that affect that metric
and taking action is far superior to arguing about how difficult it is
and doing nothing.

You're kidding yourself. Finding the things that "affect" the metric
is part of how they build models. It involves a lot of statistical
testing and regression analysis.

The relationships have limits and the relationships are usually
calculus functions.

From there, the statistics often are complex.

You can fix an error in your actions.

When? When the event occurs? The event is 40 years in the future.

You can't fix inaction.

Go ahead and try it. See what you project for China's economy and the
US economy 40 years from now. It's simple, right?

BTW, my son is just climbing down a ladder after re-roofing our
kitchen extension. Now he has to spend the rest of the day running his
latest predictive econometric model on his company's cloud-networked
SPSS system. He has a master's degree in math and a degree in
economics, and does econometric research and analysis for a top
consulting firm. I should let him talk to you, but I ate up his spare
time today by getting him to nail a square of shingles so I could
repair the furnace, which kept blowing out its pilot light, and then
watch TV. g

--
Ed Huntress