Wow, this has been on here a twice a few years back, but never had a single comment. Here's to breaking the trend.<p><a href="https://news.ycombinator.com/item?id=5814769" rel="nofollow">https://news.ycombinator.com/item?id=5814769</a><p><a href="https://news.ycombinator.com/item?id=6346156" rel="nofollow">https://news.ycombinator.com/item?id=6346156</a><p>This is from the same site, from the title looks to be prior work on the same topic, also submitted previously (6 years ago) with no comments:<p><a href="http://physics.ucsd.edu/do-the-math/2011/07/can-economic-growth-last/" rel="nofollow">http://physics.ucsd.edu/do-the-math/2011/07/can-economic-gro...</a>
This concern about economic growth in 1000+ years is entirely academic. The more relevant question is whether exponential growth (at whatever rate) is feasible for the next few decades and even centuries, and to me the answer to that question is yes, just using the examples from the article. So we can build appropriate policies for the present and near-ish future. Our descendants can decide for themselves at that point whether it's reasonable to continue economic growth, based on knowledge and science and experience they have gained.<p>I mean, how many physical theories can be argued to work into the <i>infinite</i> future? Does quantum mechanics or GR hold past the end of the universe? It's not even a meaningful question. Why hold economic models to the equivalent standard, when all that is needed is whether they hold in the relevant domain?<p>I feel that this question and argument is often used to try to draw the conclusion that we must stop trying for economic growth NOW, because <i>infinite</i> growth is impossible. Maybe it is impossible, but I don't think something happening or not happening at infinity or even in a thousand years has any bearing on what <i>we</i> should be doing <i>now</i>.
AKA: "physicist frames discussion with economist in terms of things he is intimately familiar with but economist isn't, feels smug about his own perceived superiority". Probably a reflection on his frustration with feelings of being so much smarter than those 'economists' yet not being taken half as serious. The fact that he thought this was even worth spending 2-3 hours on writing up shows more about his lack of understanding of what economics is, than what he probably thinks is an "exposure" of the inadequacies of economics as a field.<p>(not an economist, but broad-minded enough to recognize someone who has spend so much time in his own field to be completely rigid-minded about it. An affliction rather common to CS types too, I'm sad to say, since as a software engineer in research I spend quite some time around those)
I apologize for not sticking it out until the end of the article, but it got really painful about a third of the way through.<p>I am tempted to save this and put it under a file titled something like "why scientists should not be economists" but I'm afraid it's a little too involved for that purpose.<p>I mean no disrespect to the author: these all seem like good and reasonable questions. To understand why this form of analysis does not work is to cut to the heart of what the difference between economics and hard empirical sciences. I will give a couple of examples, but I fear that folks who missed it the first time around will not get it this time.<p>First, note that no matter what period in human history this conversation occurred, it would follow the same pattern. "Here is a chart of the rate of fishing from the pond near our Roman village. Certainly catastrophe awaits us in just a few years", or one that actually occurred, "Population growth will stagnate and we will have famine when the 1900s come. Why? Because we will have ran out of grazing land for all the horses we will need"<p>Growth lines can't continue forever. Seems obvious. Yet somehow it always turns out the thing you were measuring wasn't the important thing all along. Sure, you can only fish so much -- but there are other ponds. Yep, can't have that many meadows -- yet meadows aren't a constraining factor.<p>The reason why such analysis fails is that science is always seeking a constrained and known system. Given controlled conditions, the falsifiability and reproducibility of science says that given these inputs, these outputs are likely to occur. Economics, because it deals with what people want, is under no such constraints. Let's say you give everyone on the planet all the food, shelter, and healthcare they need. End of money, right? Nope. People would trade Justin Bieber concert tickets, or autographs of Elvis Presley. People always want stuff they don't have, and they always like trading for it. That's economics.<p>If economic systems were the same as physical systems, wow, we'd have a lot of physicists who have made fortunes playing the stock market. We do not.
OK, so I'm neither a physicist nor an economist. But I don't get why aggregate economic value couldn't grow indefinitely. For example, consider software.<p>Poorly written code might not be very valuable, because it's slow and crashes often. Well written code would arguably be more valuable. It would also waste less electrical energy, and produce less heat.<p>Indeed, code could do entirely new things, using less material and energy inputs, that are worth much more. Maybe I'm missing something, but that seems distinct from increasing efficiency. There's a limit to efficiency, but no limit to value.
A economic blogger's retort from a few years ago:<p><a href="http://noahpinionblog.blogspot.nl/2012/11/murphys-law.html" rel="nofollow">http://noahpinionblog.blogspot.nl/2012/11/murphys-law.html</a>
Sure there's a physical ceiling to energy generation but I feel like there's a great degree of oversimplifcation in his argument.<p>Take for example solar: right now, pretty much all of that energy (sans the work performed for propelling ocean currents and production of future fossil fuels via photosynthesis of plants) is irradiated back into space anyway. Using more of that energy to perform work on surface of Earth won't change a thing from global thermodynamics perspective. That energy is already on the books.<p>Or consider hydro (a consequence of solar itself): the moving water already carries energy and performs work. Re-purposing that energy in the form of electricity would have no impact on the overall energy budget.<p>Granted the energy growth is theoretically limited, but the limit might not be as near if we consider that much of energy generation could be essentially energy conversion.
Don't waste your brain cells on this, people, move along.<p>To the author: you scoot off to /r/badeconomics. Sure. OK. Economic growth cannot continue to look like it currently does forever. Gasp, some economists may not have ever pondered that particular limit case, given the importance to their everyday lives. I know that it was super thrilling experience for you ("That should not have happened!" as if the economist were a debate club champion and superhuman?) but trapping a man in a word game over dinner is does not mean you've shattered his profession - not even if he falls into your clever trap. The whole discussion has no bearing on what economics is or what economists do.<p>To be more concrete: what economists do involves more data, accepting that there is a use to building mathematically tractable models with limited domains of explanation even if it means some implausible assumptions in limit cases, and it certainly involves less worrying about what the world will look like 2500 years from now. I'm not saying we shouldn't care about the ultra-long-horizon future of humanity. I'm sure there are some smart people working on those issues, but econ departments are not where people do it. There are no data, no way to establish causal links that far out, no arguments that could make it into a respectable economics journal.
Impracticality of physical economic analysis aside, I'm now curious about the engineering problem of cooling down a planet overheating from sheer exothermal industry. Can you pack enough waste heat into a canister that launching it into space is a net decrease in energy? Can space elevator tethers be used for evaporative cooling into the vacuum?<p>As I recall, in Niven's books an alien race moved their planet away from its sun in order to deal with the problem, but I assume that wouldn't even buy us an order of magnitude in planetary energy dissipation capacity.
Those discussions always seem to miss the point.
I think it is really obvious that our economic system struggles with stagnation, but really seems to break if an econmy (god forbid) shrinks for whatever reason.<p>If not for that constraint i guess economies in western countries would have already shrunken quite a bit due to automatisation. For me the cause seems to be to a fundamental bug in our intertemporal trade system.
This is very unlikely to be a real conversation. A real economist would note that the economy can grow through provision of services that require very little energy relative to the value they add. Consider Google, for example. Sure, they use some electricity, but relative to their revenue that's extremely limited compared to a factory.<p>So this whole "discussion" is totally wrong-headed.
If some technology analogous to a Mr. Fusion is ever developed, then perhaps the economy could reach a point where energy is free, but heat pollution is heavily taxed.<p>The outcome would be that people start migrating into space, where heat can be rejected more freely.