(Shortsightedness and alienation can be viewed here as a kind of artificial mortality: a wayward teenager with a high liquidity preference may not actually expect to be dead in 20 years, but he expects to be someone he doesn’t much care about, which is roughly the same thing.)

The real injustice in using the safe money market rate to devalue future generations (as I modestly proposed above, #14) is that the first generation of immortals will wind up owning everything.

My grandchild, at a time when we’re both alive, acts without obvious coercion on the belief that a dollar when he’s 65 is worth substantially less than a dollar when I’m 65. I share this belief. Who stands outside time to gainsay us? Later lives are less important than earlier lives, by the revealed free preference of those who live them.

If we deplete half of an irreplaceable resource every 50 years on the exponential plan (a low 1.5% per annum liquidity preference, in a notional zero-growth economy), every generation will be able to tell the next that, at constant date, they were offered the same future value at the same age as everyone else as of that date. So no one can fairly say that her generation was shortchanged, except by the chance of birthdate and the observed time value of money set by her generation’s own lifestyle preferences. Since no one chooses her birthdate, this is the unique “fair” solution, but it does imply as a corollary that, at least with respect to irreplaceable resources, “that age is best which is the first.” Our far descendants have nothing to offer today but deeply time-discounted future labor (“what have they ever done for us?”), which is less valuable than our present labor; why should we accept their anticipatory whims at par?

In fact, this revealed-preference argument should perhaps be justly applied beyond the economic and into the political realm! Resolved, that in the interest of intergenerational fairness the sovereign franchise should be exponentially age-weighted against the young.

Imagine a one-time sudden windfall (Fred Hoyle’s gold meteorite) that needs to be divided. Equal votes gives everyone alive when it falls an equal slice. Equal worth gives everyone an equal inheritance at an equal age, so we carve off $1000 worth of meteorite for the pensioner right now, and put away $400 worth of meteorite in a money market account for the college kid’s retirement. His life is objectively cheaper: it takes a smaller slice of meteorite to give him $1000 at retirement. Yet if he has a “fair” vote, it’s hard to see why he wouldn’t want a full-sized slice right now.

Now imagine the meteorite is a big one, and we live on it.

#12 I don’t think Ramsey assumed a bliss point. And the problem of infinity is easily resolved as in Stern. Include a small probability that we either blow ourselves up or, more generally, make changes so radical that our current calculations are irrelevant. Then you get convergence nice and easily.

The result that it’s “okay” to sacrifice the present generation (actually any finite number of them) for the sake of the future is quite general.

See for example this discussion of the Koopmans axiomatization of inter temporal social welfare:

http://cepa.newschool.edu/het/essays/growth/optimal/koopaxiom.htm

Quote:
“Koopmans’s analysis suggests that if we attempt to derive a social welfare function without time preference, then we are implicitly violating sensitivity somehow. This makes sense. Without time preference, the utilities achieved by any finite number of generations can be “ignored” as the remaining infinity overwhelms them completely. Indeed, in continuous time, such negligibility is automatic.

But it is the ethical implications of this that are interesting. What Koopmans has highlighted with his exercise is the interlinkage between sensitivity with time preference. On the one hand, discounting is unethical because, say, it could be used to justify current environmentally-destructive activities whose effects would only be felt millions of years in the future. On the other hand, discounting is ethical because without it, the infinite future overwhelms the finite present. More acutely, without discounting, we could justify savagely destroying one generation now if it yielded a series of minuscule gains (no matter how small) that would accrue forever after. An ethical balance must be struck: either we count every generation equally (in which case, no single generation counts at all), or we allow discounting (in which case every generation counts, but some less than others). Which is more ethical? See Kenneth Arrow (1979) for some reflections on this.”

I’ll hold off on substantive comments until I see the paper. The sketch of the proof of the main result in the slides is too brief for me to figure out what’s going on.

Or I’ve misunderstood what you’re trying to say.

There will be a paper soon and i’ll post it here, but the PDF has the basics.

• Or you could have endogenous progress derived from increasing returns to scale in information doing much the same thing.

I never use powerpoint or any other visual aid in a videoconference situation as it’s too easy for the whole thing to fall to bits. If visuals are absolutely needed I email them to the other end in advance.

The urgent problems are, as you say, the technical one that the wide angle shot of the room full of listeners is such low definition that they all look like blurry smudges, and the lack of mutually understood social conventions for conducting a mutually satisfactory discussion.

(and I’m assuming that you’re talking about the pure rate of time preference, not stuff due to risk or the expected growth of income)

(and I also understand the argument that it may be better to assume very very very low discount rates, just in case we’re overestimating something somewhere, but that’s an argument for zero discount rates CONDITIONAL on the fact that we may be overestimating something somewhere, not an argument that we REALLY should not discount future generation’s utility.)

All that may be in there, so that’s why I ask for details.