Friday, 5 September 2014

"Limits to Growth was right. New research shows we're not nearing collapse"

Classic stuff in Guardian/Comment Is Free:

Four decades after the book was published, Limit to Growth’s forecasts have been vindicated by new Australian research. Expect the early stages of global collapse to start appearing soon.

The article includes a few charts comparing the predictions of forty years ago with actual outcomes.

So far, the predictions appear to be surprisingly accurate; they predicted rising agricultural, industrial and services output, falling birthrates and longer life expectancy. None of which is rocket science, they merely extrapolated the trend from 1900 to 1970. For example:
The original predictions were that all this will go into reverse in 2020 or thereabouts, but as we are still on the upwards trend, I'm not sure how they work that out and the article offers little in evidence apart from conjecture.

(It's like me predicting that Arsenal FC will remain in the Premiership for the next five years and then be relegated to the Championship; I can't come back in five years time and say that as they are still in the Premiership, my predictions are vindicated and next year they will definitely be relegated. Not that I know much about football.)


Ralph Musgrave said...

Bit off topic, but I think there is skullduggery behind the Guardain's phrase "comment is free". If they're simply saying it doesn't cost anything to make a comment, then that's so obvious it goes without saying. So that's not what they're saying.

What I think they ARE TRYING to suggest is that FREEDOM OF SPEECH reigns in the Guardian's comment section, which of course it doesn't. Comments after Guardian articles are more heavily censored than in any other paper, far as I can see.

The Stigler said...

The key question with all predictions/results is "why"? That data matches your predictions is sometimes meaningless because it could just be that you got lucky so far.

So, what's the "why"? Why does it turn in 2020? Are they assuming that resources run out? Or what?

And how do you predict anything in 1970, just after Borlaug made his super-efficient wheat? How did they factor in GM taking off? Were they using the oil predictions that we now know weren't right?

The huge growth happened because of neoliberalism winning. China and India have had booms since they ditched Mao's and Gandhi's ideas about planned economies.

ThomasBHall said...

TS- agreed, the why is missing. The Malthusian reason why there are limits to growth are utter bollocks, as proven by history yet continue to be argued under various guises. The Georgist "limit to growth" as an artificial barrier casued by missallocation of resources, private expropriation of rent, and huge burdens on productive enterprise is very (or at least much more) real.

Derek said...

I find the Limits to Growth stuff quite interesting. It was one of the first models to take a system dynamics approach to economics. Most economics models take a general equilibrium. Which is why most economics models can explain how a crisis happened after the event but can't forecast one.

In contrast a dynamic model can actually forecast a crisis. It might get the timing wrong but that's another matter. As it happens the LtG model has been surprisingly accurate so far given that it originally came out 40 years ago. here's hoping it doesn't continue, since if it does, we're screwed.

Bayard said...

RM, It seems pretty simple to me: the Grauniad is saying the former (i.e. stating the bleedin' obvious), but seeking to imply the latter (whilst not meaning anything of the sort, as you point out).

Graeme said...

" the LtG model has been surprisingly accurate so far"

being accurate for the wrong reasons does not count, does it?

Mark Wadsworth said...

G, they were right because they extrapolated, that's neither right nor wrong, it is a reasonable assumption.

If it was sunny yesterday, it will more than likely be sunny tomorrow etc.

Bayard said...

"If it was sunny yesterday, it will more than likely be sunny tomorrow etc."

You obviously don't live in Wales.