You write, “Mark, many thanks for your comments on projections of future income growth.”

Actually, all I got around to writing about was why the Stern Review’s assumption of 1.2% per year growth was too low, even WITHOUT the coming computer intelligence revolution. I never got around to explaining why his number is probably as much as a factor of 5-10 too low, such that per capita GDP growth in this century will probably be as much as a factor of 1000 (i.e., averaging 7% per year over the century, and resulting in every single person in the world in the year 2100 being a millionaire).

“- Do they leave out a consideration of unowned natural resources that are destroyed?”

I can’t think of any “unowned natural resources that are destroyed” that would result in my economic projections being much too high. My economic projections are much more dependent on the progress of computer intelligence (i.e., that computers costing $1000 will be comparable in capability to the human brain by ~2030), and the effect of that computer intelligence on economic growth.
http://markbahner.typepad.com/random_thoughts/2004/10/3rd_thoughts_on.html

http://markbahner.typepad.com/random_thoughts/2005/11/why_economic_gr.html

Can you name any specific “unowned natural resources that are destroyed” that you think would have an impact? (For example, in the U.S. and most developed countries, air and water are getting cleaner, not dirtier.)

“How well do such assumptions take into account demographic changes that put an increasing burden of taxes, public debt and unfunded social welfare liabilities on the dwindling youth, and risks relating to instabilities in the economic system?”

Again, my prediction of absolutely spectacular growth (averaging 7% per year or more) is averaged for the entire world. But I think the U.S. will be able to stay at or slightly below the world average growth rate.

Also, my prediction is mostly dependent on the development and economic effects of machine intelligence, but consider this: in the 20th century, the U.S. and the world experienced a severe Depression, two World Wars, and one-third to one-half of the population mired in communism for most of the century. And even with all those problems, the world averaged per-capita GDP growth over the 20th century of 1.6 percent per year (per Angus Maddison) or 2.2 percent per year (per Brad DeLong). And the post-1950 growth was even stronger than the pre-1950 growth.

So even if computers did not improve at all in capabilities, economic growth would probably be at least double the ridiculous Stern Review value of 1.2 percent per year. And even with 2.4 percent per year (double the Stern value), the per capita in 2100 would be approximately a factor of 10 higher than in 2000. And in 2200, it would be a factor of 100 higher than in 2000.

This is why, as a simple matter of economics (and morality), it doesn’t make sense to create hardship for the people of today to benefit the people of 2100 (who will be almost unimaginably better off).

http://markbahner.typepad.com/random_thoughts/2006/07/why_every_singl.html

http://markbahner.typepad.com/random_thoughts/2004/10/implications_of.html

Mark

There are certainly many anecdotal studies pointing to a lack of flora response, depending on existing other restrictions. However, when looked at globally (and logically) this is the only comprehensive study I have seen:
http://www.nasa.gov/centers/goddard/news/topstory/2003/0530earthgreen.html

Mark – I appreciate your taking the time to bring along the slower ones here on the effect of the information revolution.

Back to TT – Do you think perhaps your examples of demographic changes may have something to do with other causes of climate change – e.g. destruction of arable land *despite* increasing robustness of flora with increasing CO2? I am reminded of the lemming…

But you have not addressed a few points that merit clarification. Are you aware of where I can read up on them? Namely:

- Do they leave out a consideration of unowned natural resources that are destroyed?

- How well do such assumptions take into account demographic changes that put an increasing burden of taxes, public debt and unfunded social welfare liabilities on the dwindling youth, and risks relating to instabilities in the economic system?

Regards,

Tom

You write, “I imagine that the ‘man in the street’ has little sense of the assumptions of increased wealth, but I think that the economic discussions of it is not well-informed – as it clearly leaves out a consideration of unowned natural resources that are destroyed. Further, I am not sure how well such assumptions take into account demographic changes that put an increasing burden of taxes, public debt and unfunded social welfare liabilities on the dwindling youth, and risks relating to instabilities in the economic system.”

The Stern Review “assumptions” are indeed very dubious (even ridiculous)…but they are dubiously low, not dubiously high.

The Stern Review increase in per capita GDP by a factor of 12 from 2000 to 2200 reflects an annual per-capita GDP growth of only 1.2% per year for the next ~200 years. That might have been a reasonable assumption had it been made in 1906, but it was made in 2006!

There have been two authoritative assessments of per capita GDP over the last several hundred years: one by Angus Maddison, and the other by Brad DeLong. I will use the assessment by Maddison for the 20th century, because Maddison’s economic growth estimate is lower. (I’ll do this even though I think Brad DeLong’s assessment is probably more accurate.)

In the last 57 years, Maddison estimates that world per-capita GDP has grown by 1.2% per year or less in only 12 years, and the average over the last 57 years has been greater than 2.2% per year.

http://www.ggdc.net/maddison/Historical_Statistics/horizontal-file_03-2007.xls

From that spreadsheet, Maddison estimates an average world per-capita GDP growth from 1900 to 2003 of 1.6% per year. Using that value for 2000 to 2200 would produce an increase by a factor of 22 in per-capita GDP by 2200, versus the Stern Review’s factor of 12.

Note that DeLong’s estimate for 1900 to 2000 is approximately 2.2% per year, in contrast to Maddison’s 1.6%. Using DeLong’s 2.2% value for the period from 2000 to 2200 would produce an increase by a factor *69* by 2200 (compared to the Stern Review’s factor of 12).

I will post more later on why it’s very likely that per capita economic growth will accelerate dramatically during this century (and possibly as soon as the next 20 years).

Mark

Increasing CO2 “may” enhance flora (though plenty of studies run the other way), but I imagine you recognize that increasing temperatures have costs as well as benefits, and the costs and benefits are not uniformly distributed.

You ask me not to shoot the messenger and refer to Stern. So your reference to “the basic fact” of future wealth assumed by Stern does not betray either an acceptance of such assumptions or a value judgment that increased measured per capita wealth justifies the destruction of unowned but still valuable resources that are not included in GDP calculations?

I imagine that the “man in the street” has little sense of the assumptions of increased wealth, but I think that the economic discussions of it is not well-informed – as it clearly leaves out a consideration of unowned natural resources that are destroyed. Further, I am not sure how well such assumptions take into account demographic changes that put an increasing burden of taxes, public debt and unfunded social welfare liabilities on the dwindling youth, and risks relating to instabilities in the economic system.

TT -

You are treating the commons as a static size. It’s not. What we do know is that increasing CO2 enhances flora, which enlarges said commons.

“So let’s overheat the planet…”

Good work to get a value-laden perjorative word right up there at the start of your post

But don’t shoot the messenger, I’m only pointing out what Stern et al have said.

I honestly believe that the “man in the street” does not realise that according to Stern’s worst case, the global GDP will be 8 times higher rather than 10 times higher in 200 years (or whatever his precise figures are). I think this is one pertinent bit of information in the debate that has been completely buried under talk of recession and catastrophe.

I’d be interested to know if you disagree on either point (its relevance or how well understood it is).

“If you craft your message based on which partisans use some of your words in a political way then you’re a sellout.”

If you`re at all concerned about the issue which you are addressing, then wouldn`t carefully considering how your words might be misused simply be part of the territory, rather than a sellout?

It`s also not as if you have no leverage over the reporters you speak with, and no ways of expressing displeasure or clearing up the record.

Good luck with the struggle!

“I don’t love the ‘monster’ quote and wouldn’t be comfortable following up on it and giving it more fuel”

and then going on to give her a bunch of material to use such as

“Looking beyond the ‘monster’ quote, we need to see climate change as a risk problem. Risk implies danger and uncertainty. Governments need to help their constituencies and businesses see the climate change risk and give them some realistic targets.”

well hey, guess what she printed? the monster quote and nothing else. then the Broad piece where he asked me some questions about the Gore movie. So what do you do? You either hang up on every reporter who makes an unsolicited call to you (Fleck wouldn’t like that), or you have stock talking points that you never deviate from like the most wooden politician, or you try to say what you believe, which is that there are a shitload of subtleties in climate science that don’t get communicated well, and in saying that you let the chips fall and hope they fall ok. That’s what I’ve done so far and you’re right, it has turned more into an icon game than an issue game.

But one thing I’m not going to do is stop calling things like I see them just because Inhofe or Cato or somebody like that grabs what I’ve written and highlights it. I’ve written plenty that could be used by the other side, too, including a few slams on Inhofe in this blog. If you craft your message based on which partisans use some of your words in a political way then you’re a sellout.