[pzone]

Don't waste your brain cells on this, people, move along.

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.

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.

[carlob]

I also didn't much like the tone of the article (and I'm a physicist). However there is something to be said about working with data and not being aware of the most fundamental approximations you've done, how long can they hold, under what assumptions they will break.

As a familiar example in physics, take Hooke's law: a spring will try to retract with a force that is proportional to its extension. I think everyone will agree that this is only an approximation, and as soon as you start pulling too much you'll get out of the linear regime, or if you pull long and hard enough you'll start seeing plastic effects and the spring will change shape permanently.

This is to say that having a linear model of springs or an exponential model of economic growth is very useful, but it is important to train scholars to know the limits of their approximations so that they can recognize the need to use a more complex theory.

[markvdb]

Did you just say that research about our far out economic future is not supposed to be a job of academic economists?

It doesn't have to be a main research area for all of them, but it _should_ be for some. And all economists should know the basics (physical limitations, ...) about this area of economics.

P.S. Always interested in some decent reading material about this one!

[pzone]

I said there is very little that can be said scientifically using economic methods about the distant future. You may as well be talking to Singularity crowd, global warming scientists, asteroid impact researchers, or SETI. GDP growth researchers should follow Wittgenstein's advice.

There's far too much that we don't know about the economy right now to include wild speculation, even if it's mysterious and thrilling, in the category of economic knowledge.

[npunt]

It sounds like just the type of thing that has no use until one day it suddenly does. Ideas like these need a long time to gestate - better to do that before they're needed rather than after.

[paulojreis]

I also got the feeling of this being no more than hard-science-guy bashing the soft-sciences-guy.

As an admitted guy-in-the-middle, I'll add this deliberate provocation to the physicist/hard science guy: if the soft science guy dealt with simple systems as the ones you study [1], then maybe he would care about 100% abstract/infinitely-proof theories.

[1] Simple, as in, without complex organisms and interactions. Simple, as in, with less (or a finite set of) variables to account for.