gjm

• gjm 25 Feb 2020 15:14 UTC

  2 points

  in reply to: Long try's comment on: How does elec­tric­ity work liter­ally?

  The wa­ter (or, rather, the elec­tric­ity) sloshes to and fro 50 times a sec­ond, so there’s never enough de­lay be­tween flick­ing the switch and get­ting us­able power that a hu­man be­ing would no­tice. Typ­i­cally other things are slower; e.g., if you’re turn­ing on an in­can­des­cent light­bulb then it may take longer than that for the fila­ment to get hot enough that it starts glow­ing. For many de­vices (e.g., your phone) there is a con­verter de­vice, and when you at­tach your phone to its USB wall-plug it’s get­ting DC elec­tric­ity from it.

  It would be pos­si­ble to have some sort of con­verter for ev­ery house­hold, but ev­ery such con­verter has some losses, and many de­vices are perfectly happy just run­ning off AC, and ones that aren’t don’t nec­es­sar­ily all want the same op­er­at­ing voltage. Again, if we were do­ing ev­ery­thing from scratch now it might be worth con­sid­er­ing some­thing like that (or it might not; the de­tails mat­ter and I’m not an elec­tri­cal en­g­ineer my­self), but we have a ba­si­cally-work­ing sys­tem and re­plac­ing it whole­sale with some­thing new would need to be a big im­prove­ment to be worth the tremen­dous cost and in­con­ve­nience.

  It would be more ac­cu­rate to say that de­vices use the en­ergy in the elec­tro­mag­netic field rather than the ki­netic en­ergy of elec­trons, as such. (There isn’t a clear dis­tinc­tion be­tween us­ing the elec­tric field and us­ing the mag­netic field; the two are very in­ti­mately linked and, e.g., if two ob­servers are mov­ing rapidly rel­a­tive to one an­other, then what one sees as the elec­tric field the other may see as the mag­netic field.)

  The mo­tor in an elec­tric fan works some­thing like this. (Un­for­tu­nately it in­volves effects that don’t have a close analogue in terms of flow­ing wa­ter.) There are coils of wire. You pass an al­ter­nat­ing cur­rent through these coils; chang­ing cur­rents gen­er­ate a mag­netic field. (This isn’t meant to be ob­vi­ous. It was one of the big dis­cov­er­ies of 19th-cen­tury physics.) There’s a lump of iron placed so that this mag­netic field pulls on it. A bit of en­g­ineer­ing in­ge­nu­ity lets you ar­range these el­e­ments so that the effect is to make a shaft keep turn­ing in a con­sis­tent di­rec­tion. You mount your fan blades on that shaft. (Don’t take my de­scrip­tion too liter­ally. An ac­tual de­sign might e.g. have the wires on the shaft and the big lumps of iron on the out­side, not mov­ing.) In terms of in­di­vi­d­ual elec­trons: a mov­ing elec­tron pro­duces a mag­netic field that “curls around” its path; a whole lot of elec­trons mov­ing along a con­duc­tor pro­duce a mag­netic field that curls around those con­duc­tors; if you wind that con­duc­tor into a coil, you get a mag­netic field run­ning along the length of the coil.

  The de­tails of how en­ergy flows from place to place in all this are sub­tle and I will prob­a­bly get them wrong if I try to go into de­tails. As an ex­am­ple: sup­pose you sup­ply elec­tric­ity to some sys­tem by means of a pair of par­allel wires with op­po­site cur­rents flow­ing in them; then the en­ergy flow in the sys­tem hap­pens out­side the wires, not in­side them. (It hap­pens near to the wires, and the en­ergy flows par­allel to the wires.)

  (Just to re­it­er­ate: this isn’t a mat­ter of elec­trons flow­ing into the de­vice and be­ing con­sumed, just as a hy­drauli­cally pow­ered sys­tem that works by hav­ing wa­ter turn tur­bine blades doesn’t work by con­sum­ing the wa­ter.)

  I think most of the power con­sump­tion in (the pro­cess­ing parts of) a com­puter is re­sis­tive losses—i.e., the thing where en­ergy from the elec­tric field gets trans­ferred to ki­netic en­ergy in the elec­trons and/​or atoms and heats things up. In an ideal­ized max­i­mally-effi­cient com­put­ing de­vice, it turns out that the one thing that un­avoid­ably costs en­ergy is dis­pos­ing of in­for­ma­tion, and some peo­ple have spec­u­lated about “re­versible com­put­ing” that never erases bits or oth­er­wise throws in­for­ma­tion away; but real com­put­ing de­vices are sev­eral or­ders of mag­ni­tude away from be­ing limited by these con­sid­er­a­tions.

  I be­lieve a fridge uses elec­tri­cal en­ergy mostly in mo­tors, which work in much the same way as the mo­tor in a fan. Th­ese mo­tors then drive other in­ter­est­ing sys­tems that e.g. com­press fluids and pump them around and so forth—I don’t know any of the de­tails off­hand—but elec­tric­ity is not di­rectly in­volved in those mechanisms.

  As I hope I’ve already made clear, I’m not re­ally an ex­pert on this, and quite pos­si­bly no other LW reg­u­lars are ei­ther. You might do bet­ter to find e.g. a text­book on elec­tro­mag­netism. (But be warned: if you read a text­book on elec­tro­mag­netism that goes deep enough to an­swer your ques­tions, you will end up hav­ing to do quite a lot of maths.)

• gjm 24 Feb 2020 16:13 UTC

  16 points

  on: How does elec­tric­ity work liter­ally?

  The speed at which elec­tri­cal sig­nals prop­a­gate is much faster than the speed at which elec­trons move in an elec­tri­cal con­duc­tor. (Pos­si­bly helpful metaphor: sup­pose I take a broom­stick and poke you with it. You feel the poke very soon af­ter I start shov­ing the stick, even though the stick is mov­ing slowly. You don’t need to wait un­til the very same bit of wood I shoved reaches your body.)

  The speed at which elec­tri­cal sig­nals prop­a­gate is slower than the speed of light, but it’s a sub­stan­tial frac­tion of the speed of light and it doesn’t de­pend on the speed at which the elec­trons move. (It may cor­re­late with it—e.g., both may be a con­se­quence of how the elec­trons in­ter­act with the atoms in the con­duc­tor. Un­der­stand­ing this right is one of the quan­tum-me­chan­i­cal sub­tleties I men­tion be­low.)

  When cur­rent flows through a con­duc­tor with some re­sis­tance, some of the en­ergy in the flow of the elec­trons gets turned into ran­dom-ish mo­tion in the ma­te­rial, i.e., heat. This will in­deed make the elec­trons move more slowly but (see above) this doesn’t make much differ­ence to the speed at which elec­tri­cal effects prop­a­gate through the con­duc­tor.

  (What ac­tu­ally hap­pens in elec­tri­cal con­duc­tors is more com­pli­cated than in­di­vi­d­ual elec­trons mov­ing around, and un­der­stand­ing it well in­volves quan­tum-me­chan­i­cal sub­tleties, of most of which I know noth­ing to speak of.)

  It is not usual to con­vert AC to DC us­ing re­lays.

  It is true that if you take AC power, rec­tify it us­ing the sim­plest pos­si­ble cir­cuit, and use that to sup­ply a DC de­vice then it will al­ter­nate be­tween be­ing pow­ered and not be­ing pow­ered—and also that dur­ing the “pow­ered” pe­ri­ods the voltage it gets will vary. Some de­vices can work fine that way, some not so fine.

  In prac­tice, AC-to-DC con­ver­sion doesn’t use the sim­plest pos­si­ble cir­cuit. It’s pos­si­ble to smooth things out a lot so that the de­vice be­ing pow­ered gets some­thing close to a con­stant DC sup­ply.

  But there are similar effects even when no rec­tifi­ca­tion is be­ing done. You men­tioned flick­er­ing lights, and un­til re­cently they were an ex­am­ple of this. If you power an in­can­des­cent bulb us­ing AC at 50Hz then the amount of cur­rent flow­ing in it varies and ac­cord­ingly so does the light out­put. (At 100Hz, not 50Hz; figur­ing out why is left as an ex­er­cise for the reader.) How­ever, be­cause it takes time for the fila­ment to heat up and cool down the ac­tual fluc­tu­a­tion in light out­put is small. Fluores­cent bulbs re­spond much faster and do flicker, and some peo­ple find their light very un­pleas­ant for ex­actly that rea­son. LED lights, in­creas­ingly of­ten used where in­can­des­cents and fluores­cents used to be, are DC de­vices. I think there’s a wide va­ri­ety in the cir­cuitry used to power them, but most will flicker at some rate. Good ones will be driven in such a way that they flicker so fast you will never no­tice it. (Some­where in the kHz range.)

  Some­times DC (at high voltages) is used for power trans­mis­sion. I think AC is used, where it is used, be­cause con­ver­sion be­tween (typ­i­cally very high) trans­mis­sion voltage and the much lower voltages con­ve­nient for ac­tual use is easy by means of trans­form­ers; trans­form­ers only work for AC. (Be­cause they de­pend on elec­tro­mag­netic in­duc­tion, which works on the prin­ci­ple that changes in cur­rent pro­duce mag­netic fields and changes in mag­netic field pro­duce cur­rents.) I don’t know whether AC or DC would be a bet­ter choice if we were start­ing from scratch now, but both sys­tems were pro­posed and tried very early in the his­tory of elec­tri­cal power gen­er­a­tion and I’m pretty sure all the ob­vi­ous ar­gu­ments on both sides were aired right from the start.

  When a de­vice “con­sumes” elec­tri­cal en­ergy it isn’t ab­sorb­ing elec­trons. (In that case it would have to ac­cu­mu­late a large elec­tri­cal charge. That’s usu­ally a Bad Thing.) It’s ab­sorb­ing (or us­ing in some other way) en­ergy car­ried in the elec­tric field. It might help to imag­ine a sys­tem that trans­mits en­ergy hy­drauli­cally in­stead, with ev­ery house­hold equipped with high-pres­sure pipes, with a con­stant flow of wa­ter main­tained by the wa­ter-power com­pany, and op­er­at­ing its equip­ment us­ing tur­bines. Th­ese wouldn’t con­sume wa­ter un­less there were a leak; in­stead they would take in fast-mov­ing wa­ter and re­turn slower-mov­ing wa­ter to the sys­tem. An “AC” hy­draulic sys­tem would have wa­ter mov­ing to and fro in the pipes; again, the wa­ter wouldn’t be con­sumed, but en­ergy would be trans­ferred from the wa­ter-pipes to the de­vices be­ing op­er­ated. Pow­er­ing things with elec­tric­ity is similar.

• gjm 18 Feb 2020 15:45 UTC

  2 points

  in reply to: Benquo's comment on: REVISED: A drown­ing child is hard to find

  I’m point­ing out what seem to me to be large and im­por­tant holes in your ar­gu­ment.

  To an ob­jec­tion of the form “You have given no good rea­son to think Y fol­lows from X”, it is not rea­son­able to re­spond with “You need to give a spe­cific ex­am­ple of how you can have X and not Y, with re­al­is­tic num­bers in it”.

  I claim that you have given no rea­son to think that if there’s a lot of good to be done at $5k per life-equiv­a­lent then there is nec­es­sar­ily an ex­per­i­ment that it’s fea­si­ble for (say) GiveWell to con­duct that would do some­thing like elimi­nat­ing all malaria deaths in Mada­gas­car for a year. You’ve just said that ob­vi­ously there must be.

  I re­ject any norms that say that in that situ­a­tion any­one say­ing that your rea­son­ing has gaps in is obliged to show con­crete coun­terex­am­ples.

  How­ever, be­cause I’m an obliging sort of chap, let’s have a go at con­struct­ing one and see what hap­pens. (But, for the avoidance of doubt, I am not con­ced­ing that if my spe­cific coun­terex­am­ple turns out not to work then it means your claim is right and mine is wrong. Of course it’s pos­si­ble that you know ahead of time that I can’t con­struct a work­ing coun­terex­am­ple, on ac­count of hav­ing a bet­ter un­der­stand­ing than mine of the situ­a­tion—but, again, in that case com­mu­ni­cat­ing that bet­ter un­der­stand­ing should be part of your ar­gu­ment.) I’ll look at Mada­gas­car since that’s the coun­try you men­tioned speci­fi­cally.

  [EDITED to add:] Although the fore­go­ing para­graph talks about “con­struct­ing a coun­terex­am­ple”, in fact what I did in the fol­low­ing para­graphs is just to make some guesses about num­bers and see where they lead; I wasn’t try­ing to pick num­bers that are max­i­mally per­sua­sive or any­thing.

  So, first of all let’s find some num­bers. Mada­gas­car has a pop­u­la­tion of about 26 mil­lion. Malaria is the 7th most com­mon cause of death there. If I’m read­ing the stats cor­rectly, about 10% of the pop­u­la­tion has malaria and they have about 6k deaths per year. Essen­tially the en­tire pop­u­la­tion is con­sid­ered at risk. At pre­sent Mada­gas­car gets about $50M/​year of malaria-fight­ing from the rest of the world. In­sec­ti­cide-treated bed nets allegedly re­duce the risk of get­ting malaria by ~70% com­pared with not hav­ing them; it’s not clear to me how that’s defined, but let’s sup­pose it’s per year. The statis­tics I’ve seen differ some­what in their es­ti­mates of what frac­tion of the Mada­gas­can pop­u­la­tion has ac­cess to bed nets; e.g., in this doc­u­ment from the WHO plot E on page 85 seems to show only ~5% of the pop­u­la­tion with ac­cess to ei­ther bed nets or in­door spray­ing; the table on page 117 says 6%; but then an­other table on page 122 es­ti­mates ~80% of house­holds have at least one net and ~44% have at least one per two peo­ple. I guess maybe most Mada­gas­can house­holds have a great many peo­ple? Th­ese figures are much lower in Mada­gas­car than in most of Africa; I don’t know why. It seems rea­son­able to guess that bed net char­i­ties ex­pect it to be more ex­pen­sive, more difficult or less effec­tive in Mada­gas­car than in the other places where they have dis­tributed more nets, but again even if this is cor­rect I don’t know what the un­der­ly­ing rea­sons are. I ob­serve that sev­eral Afri­can coun­tries have a lot more malaria deaths per unit pop­u­la­tion; e.g., Niger has slightly fewer peo­ple than Mada­gas­car but nearly 3x as many malaria deaths. (And also about 3x as many peo­ple with malaria.) So maybe bed net dis­tri­bu­tion fo­cuses on those coun­tries?

  So, my first ob­ser­va­tion is that this is all con­sis­tent with the poss­bil­ity that the num­ber of lives save­able in Mada­gas­car at ~$5k/​life is zero, be­cause of some com­bi­na­tion of { lower prevalence of malaria, higher cost of dis­tribut­ing nets, lower effec­tive­ness of nets } there com­pared with, say, Niger or the DRC. This seems like the sim­plest ex­pla­na­tion of the fact that Mada­gas­car has sur­pris­ingly few bed nets per per­son, and it seems con­sis­tent with the fact that, while it cer­tainly has a se­vere malaria prob­lem, it has sub­stan­tially less malaria per per­son than many other Afri­can coun­tries. Let’s make a hand­wavy guess that the effec­tive­ness per dol­lar of bed­nets in Mada­gas­car is half what it is in the coun­tries with the best effec­tive­ness-per-dol­lar op­por­tu­ni­ties, which con­di­tional on that $5k/​life-equiv­a­lent figure would mean $10k/​life-equiv­a­lent.

  Now, as to fatal­ity: ev­i­dently the huge ma­jor­ity of peo­ple with malaria do not die in any given year. (~2.5M cases, ~6k deaths.) Malaria is a se­ri­ous dis­ease even when it doesn’t kill you. Back of en­velope: sup­pose deaths from malaria in Mada­gas­car cost 40 QALYs each (life ex­pec­tancy in Mada­gas­car is ~66y, many malaria deaths are of young chil­dren but not all, there’s a lot of other dis­ease in Mada­gas­car and I guess qual­ity of life is of­ten poor, hand­wave hand­wave; 40 QALYs seems like the right bal­l­park) and sup­pose hav­ing malaria but not dy­ing costs 0.05 QALYs per year (it puts you com­pletely out of ac­tion some of the time, makes you feel ill a lot more of the time, causes men­tal dis­tress, some­times does last­ing or­gan dam­age, etc.; again I’m mak­ing hand­wavy es­ti­mates). Then ev­ery year Mada­gas­car loses ~125k QALYs to non­fatal malaria and ~240k QALYs to fatal malaria. Those num­bers are su­per-in­ex­act and all I’m re­ally com­fortable con­clud­ing here is that the two are com­pa­rable. I guess (though I don’t know) that bed­nets are some­where around equally effec­tive in keep­ing adults and chil­dren from get­ting malaria, and that there isn’t any cor­re­la­tion be­tween pre­ventabil­ity-by-bed­net and sever­ity in any par­tic­u­lar case; so I ex­pect the benefits of bed­nets in death-re­duc­tion and other-ill­ness-re­duc­tion to, again, be com­pa­rable. I be­lieve death, when it oc­curs, is com­monly soon af­ter in­fec­tion, but the other effects com­monly per­sist for a long time. I’m go­ing to guess that ³⁄₄ of the effects of a change in bed­net use hap­pen within ~ a year, with a long tail for the rest.

  So, let’s put that to­gether a bit. Most of the pop­u­la­tion is not cur­rently pro­tected by bed­nets. If they sud­denly were then we might ex­pect a ~70% re­duc­tion in new malaria cases that year, for those pro­tected by the nets. Best case, that might mean a ~70% re­duc­tion in malaria deaths that year; pre­sum­ably the ac­tual figure is a bit less be­cause some malaria deaths hap­pen longer af­ter in­fec­tion. Call it 60%. Re­duc­tion in malaria harm that year would be more like 50%. Cost would be $10k per life-equiv­a­lent saved. To­tal cost some­where on the or­der of $50M, a sub­stan­tial frac­tion of e.g. AMF’s to­tal as­sets.

  Another way to es­ti­mate the cost: GiveWell es­ti­mates that AMF’s bed­net dis­tri­bu­tion costs some­where around $4.50 per net. So one net per per­son in Mada­gas­car is $100M or so.

  But that’s only ~60% of the deaths; you wanted a nice clear-cut ex­per­i­ment that got rid of all the malaria deaths in Mada­gas­car for one year. And in­deed cut­ting deaths by 60% would not nec­es­sar­ily be con­clu­sive, be­cause the an­nual vari­a­tion in malaria cases in Mada­gas­car seems to be large and so is the un­cer­tainty in count­ing those cases. In the 2010-2017 pe­riod the point es­ti­mates in the doc­u­ment I linked above have been as low as ~2200 and as high as ~7300; the er­ror bars each year go from just barely above zero to nearly twice the point es­ti­mate. (Th­ese un­cer­tain­ties are much larger, in­ci­den­tally, than in many other Afri­can coun­tries with similar malaria rates, which seems con­sis­tent with there be­ing some­thing about Mada­gas­car that makes treat­ment and/​or mea­sure­ment harder than other Afri­can coun­tries.)

  To get rid of all (or nearly all) the deaths in one year, pre­sum­ably you need to elimi­nate in­fec­tion that hap­pens while peo­ple aren’t sleep­ing un­der their bed nets, and to deal with what­ever minor­ity of peo­ple are un­will­ing or un­able to use bed nets. Those seem like harder prob­lems. I think coun­tries that have elimi­nated malaria have done it by elimi­nat­ing the mosquitoes that spread it, which is a great long-term solu­tion if you can do it but much harder than dis­tribut­ing bed nets. So my best guess is that if you want to get rid of all the malaria, even for one year, you will have to spend an awful lot more per life-equiv­a­lent saved that year; I would be un­sur­prised by 10x as much, not that sur­prised by 100x, and not al­to­gether as­ton­ished if it turned out that no one ac­tu­ally knows how to do it for any amount of money. It might still be worth it if the costs are large—the fu­ture effects are large if you can elimi­nate malaria from a place per­ma­nently. (Which might be eas­ier in Mada­gas­car than in many other Afri­can coun­tries, since it’s an is­land.) But it puts the costs out of the range of “things ex­ist­ing EA char­i­ties could eas­ily do to prove a point”. And it’s a Gates Foun­da­tion sort of pro­ject, not an AMF one, and in­deed as I un­der­stand it the Gates Foun­da­tion is putting a lot of money into in­ves­ti­gat­ing ways to elimi­nate malaria.

  Ten­ta­tive con­clu­sion: It’s not a all ob­vi­ous to me that this sort of ex­per­i­ment would be worth while. For “only” an amount of money com­pa­rable to the to­tal as­sets of the Against Malaria Foun­da­tion, it looks like it might be pos­si­ble to some­what-more-than-halve malaria deaths in Mada­gas­car for one year (and re­duce on­go­ing malaria a bit in sub­se­quent years). The ex­pected benefits of do­ing this would be sub­stan­tially less than those of dis­tribut­ing bed nets in the prob­a­bly-more-cost-effec­tive other places where or­ga­ni­za­tions like AMF are cur­rently putting them. Given how vari­able the prevalence of malaria is in Mada­gas­car, and how un­cer­tain the available es­ti­mates of that prevalence seem to be, it is not clear that do­ing this would be any­thing like con­clu­sive ev­i­dence that bed­net dis­tri­bu­tion is as effec­tive as it’s claimed to be. (All of the fore­go­ing is con­di­tional on the as­sump­tion that it is as effec­tive as claimed.) To get such con­clu­sive ev­i­dence, it would be nec­es­sary to do things rad­i­cally differ­ent from, and prob­a­bly far more ex­pen­sive than, bed­net dis­tri­bu­tion; or­ga­ni­za­tions like AMF would have nei­ther the ex­per­tise nor the re­sources to do that.

  I am not very con­fi­dent about any of the num­bers above (other than “easy” ones like the pop­u­la­tion of Mada­gas­car), and all my calcu­la­tions are hand­wavy es­ti­mates (be­cause there’s lit­tle point do­ing any­thing more care­ful when the un­der­ly­ing num­bers are so doubt­ful). But what those calcu­la­tions sug­gest to me is that, whether or not do­ing the sort of ex­per­i­ment you pro­pose would be a good idea, it doesn’t seem to be an ob­vi­ously good idea (since, in par­tic­u­lar, my cur­rent best es­ti­mate is that it would not be a good idea). There­fore, un­less I am shown com­pel­ling ev­i­dence point­ing in a differ­ent di­rec­tion, I can­not take se­ri­ously the claim that EA or­ga­ni­za­tions that aren’t do­ing such ex­per­i­ments show thereby that they don’t be­lieve that there is large scope for do­ing good at a price on the or­der of $5k per life-equiv­a­lent.

• gjm 16 Feb 2020 19:44 UTC

  2 points

  in reply to: George's comment on: Why Science is slow­ing down, Univer­si­ties and Maslow’s hi­er­ar­chy of needs

  I can well be­lieve that uni­ver­si­ties used to work well and wors­ened over time. The point of my ques­tion at the end there is that I would ex­pect any New Im­proved Univer­sity Re­place­ment to suffer the same pro­cess.

  (Of course it might be worth it any­way, if it works bet­ter for long enough.)

• gjm 16 Feb 2020 13:11 UTC

  2 points

  in reply to: George's comment on: Why Science is slow­ing down, Univer­si­ties and Maslow’s hi­er­ar­chy of needs

  I agree that you can make a case that send­ing a lot of peo­ple to uni­ver­sity is waste­ful; maybe you can make a case that send­ing any­one to uni­ver­sity is waste­ful (though, for what it’s worth, that feels en­tirely wrong to me). But shminux was mak­ing a differ­ent claim: that our uni­ver­si­ties are so waste­ful that they im­peril our civ­i­liza­tion’s sur­vival. That claim seems ab­surdly overblown to me.

  Yes, the age at which peo­ple go to uni­ver­sity is a good age for learn­ing new things. That would be why peo­ple of that age are of­ten en­couraged to go off to a place de­signed for learn­ing new things: a uni­ver­sity.

  Maybe just get­ting a job will (on av­er­age) ac­tu­ally re­sult in learn­ing more valuable things, but frankly I don’t see any rea­son to be­lieve that. (More things valuable for be­com­ing a cog in some­one else’s in­dus­trial ma­chine, maybe, though even that isn’t ob­vi­ous.)

  Maybe all young peo­ple (or at least all fairly bright young peo­ple?) should be try­ing to start their own busi­nesses, but again I see no rea­son to be­lieve that ei­ther. Start­ing a busi­ness is hard; most new busi­nesses fail; most 18-year-olds lack knowl­edge and ex­pe­rience that would greatly im­prove their chances of start­ing a suc­cess­ful busi­ness. (There are other rea­sons why I think this would be a bad idea, but since I’m not even sure it’s what you have in mind I’ll leave it there.)

  Maybe the learn­ing peo­ple cur­rently do at uni­ver­si­ties, or the learn­ing they’re meant to be do­ing at uni­ver­si­ties, or what­ever other learn­ing should re­place it, should be done “in the back­ground” while they are work­ing a job; but I see no rea­son to think that’s even pos­si­ble in most cases. Their jobs are likely to be too de­mand­ing in time, effort and men­tal fo­cus. For sure some peo­ple can do it, but if you want it to be the gen­eral case then I’d like to see ev­i­dence that it’s fea­si­ble.

  Maybe we need differ­ent ways of op­ti­miz­ing 18-20-year-olds’ lives for learn­ing new and valuable things. I’d be in­ter­ested to see con­crete pro­pos­als. An ob­vi­ous ques­tion I hope they’d ad­dress: why ex­pect that in prac­tice this will end up bet­ter than uni­ver­si­ties?

• gjm 16 Feb 2020 1:26 UTC

  4 points

  in reply to: shminux's comment on: Why Science is slow­ing down, Univer­si­ties and Maslow’s hi­er­ar­chy of needs

  So the usual story about Easter Is­land is that con­struc­tion and trans­porta­tion of the stat­ues used up all their palm trees, and the is­land’s ecosys­tem de­pended on the palm trees, so they starved to death or some­thing. (I think there’s some doubt about whether that’s ac­tu­ally right, but it’s a plau­si­ble enough story and a use­ful anal­ogy even if it turns out not to be liter­ally true.)

  What re­source are uni­ver­si­ties in dan­ger of con­sum­ing all of?

  Money? US spend­ing on uni­ver­si­ties seems to be on the or­der of a cou­ple of per­cent of GDP.

  Re­searcher time? Even sup­pos­ing that uni­ver­sity re­search is worth­less, there’s a lot of re­search be­ing done by cor­po­rate R&D de­part­ments, and OP here gives some ex­am­ples to sug­gest that some of it’s pretty good. (And, for what it’s worth, I don’t find it plau­si­ble that uni­ver­sity re­search is worth­less, though no doubt some of it is.)

  Stu­dents’ youth? Even sup­pos­ing that time spent at uni­ver­sity is worth­less, it’s only a few years per per­son. (And, for what it’s worth, I don’t find it plau­si­ble that time spent at uni­ver­sity is worth­less. I know that at uni­ver­sity I both had fun and learned things I am still glad to know; maybe I was ex­cep­tion­ally lucky but I don’t know of any good rea­son to think so.)

• gjm 13 Feb 2020 16:22 UTC

  2 points

  in reply to: Benquo's comment on: REVISED: A drown­ing child is hard to find

  So I as­sume you’re ob­ject­ing to his state­ment near the end that “the es­ti­mate that you can save a life for $5000 re­mains prob­a­bly true (with nor­mal caveats about un­cer­tainty)”, on the ba­sis that he should ac­tu­ally say “you prob­a­bly can’t re­ally save a life for $5000 be­cause if you give that $5000 then the ac­tual re­sult will be that Good Ven­tures gives less in fu­ture be­cause GiveWell will make sure of that to en­sure that alleged $5000 op­por­tu­ni­ties con­tinue to ex­ist for PR rea­sons”.

  But I don’t see the alleged switch­ing back and forth. So far as I can see, Scott sim­ply dis­agrees with you about the in­tertem­po­ral fung­ing thing, per­haps for the same rea­son as I think I do (namely, that GiveWell’s ac­tual state­ments about their recom­men­da­tions to Good Ven­tures speci­fi­cally claim that they are try­ing to make them in a way that doesn’t in­volve in­tertem­po­ral fung­ing of a sort that messes up in­cen­tives in the way you say it does).

  Where do you think Scott’s com­ment as­sumes the “steep diminish­ing re­turns story”?

  It does tell a steep-diminish­ing-re­turns story about the spe­cific idea of try­ing to run the sort of ex­per­i­ment you pro­pose. But part of his point is that that sort of ex­per­i­ment would likely be in­effi­cient and im­prac­ti­cal, un­like just con­tin­u­ing to do what AMF and similar char­i­ties are already do­ing with what­ever fund­ing is available to them. The diminish­ing re­turns are differ­ent in the two sce­nar­ios, and it could be that they are much steeper if you de­cide that your goal is to elimi­nate all malaria deaths on Mada­gas­car than if your goal is to re­duce malaria in all the ar­eas where there’s a lot of malaria that can be ad­dressed via bed nets. It can si­mul­ta­neously be true that (1) there are read­ily available op­por­tu­ni­ties to save more than 6k ex­tra lives by dis­tribut­ing more bed nets, at a cost of $5k per life saved, and that (2) if in­stead you want to save speci­fi­cally all 6k peo­ple who would oth­er­wise have died from malaria in Mada­gas­car this year, then it will cost hugely more than $5k per life. And also, re­lat­edly, that (3) if in­stead of this vague “you” we start try­ing to be spe­cific about who is go­ing to do the thing, then in case 1 the an­swer is that AMF can save those lives by dis­tribut­ing bed nets, a spe­cific thing that it knows how to do well, whereas in case 2 the an­swer is that there is no or­ga­ni­za­tion that has all the com­pe­tences re­quired to save all those lives at once, and that mak­ing it hap­pen would re­quire a tremen­dous feat of co­or­di­na­tion.

• gjm 13 Feb 2020 16:08 UTC

  2 points

  in reply to: Benquo's comment on: REVISED: A drown­ing child is hard to find

  It’s a bit like the differ­ence be­tween “Ben thinks Gareth is giv­ing too much money to the Against Malaria Foun­da­tion” and “Ben thinks Gareth isn’t let­ting enough ba­bies die of malaria”, in the con­text of a dis­cus­sion about how in­di­vi­d­u­als should al­lo­cate their money.

• gjm 13 Feb 2020 16:02 UTC

  5 points

  in reply to: Benquo's comment on: REVISED: A drown­ing child is hard to find

  I think you have the bur­den of proof in the wrong place. You are claiming that if there’s a lot of good to be done at $5k then there must be ex­per­i­ments that are ob­vi­ously worth pour­ing a lot of re­sources into. I’m sim­ply say­ing that that’s far from clear, for the rea­sons I gave. If it turns out that ac­tu­ally fur­ther de­tails of the situ­a­tion are such as to mean that there must be good ex­per­i­ments to do, then your ar­gu­ment needs to ap­peal to those fur­ther de­tails and ex­plain how they lead to that con­clu­sion.

  I am not mak­ing any spe­cific claim about what frac­tion of malaria deaths are from in­fec­tion in prior years, or what pro­por­tion can be pre­vented at ~$5k per life-equiv­a­lent, etc. To what­ever ex­tent those are rele­vant to the cor­rect­ness of your claim that EA or­ga­ni­za­tions would be run­ning the sort of ex­per­i­ments you pro­pose if they re­ally be­lieved their num­bers, your ar­gu­ment for that claim should already be in terms of those figures.

• gjm 13 Feb 2020 1:24 UTC

  2 points

  on: Sus­pi­ciously bal­anced evidence

  I’m see­ing a lot of replies say­ing, in effect, “duh, ob­vi­ously #1: we only bother think­ing about the ques­tions whose an­swers are still some­what open to doubt”. Maybe that’s the whole story, but I still don’t think so: some ques­tions re­main in the cat­e­gory of “ques­tions many peo­ple think about and aren’t close to cer­tain of the an­swers to” even as a lot of ev­i­dence ac­cu­mu­lates.

  (But maybe #1 is more of the story than I was in­clined to think.)

• gjm 12 Feb 2020 19:46 UTC

  2 points

  in reply to: G Gordon Worley III's comment on: Sus­pi­ciously bal­anced evidence

  Can you sug­gest a bet­ter way of fram­ing the ques­tion?

  (I’m not very sure what sort of adding-up-to-nor­mal­ity you have in mind; are you say­ing my “good ex­pla­na­tion #1” is likely the cor­rect one?)

Sus­pi­ciously bal­anced evidence

• gjm 11 Feb 2020 12:08 UTC

  2 points

  in reply to: diegocaleiro's comment on: Causal Universes

  I think prob­a­bly Pen­rose’s “The Road to Real­ity” was in­tended. I don’t think there’s any­thing in the Deutsch book like “cur­va­ture of space­time is de­ter­mined by in­finites­i­mal light cones”; I don’t think I’ve read the rele­vant bits of the Pen­rose but it seems like ex­actly the sort of thing that would be in it.

• gjm 10 Feb 2020 17:09 UTC

  2 points

  in reply to: Kaj_Sotala's comment on: Open & Wel­come Thread—Fe­bru­ary 2020

  Nice to see that Steven Pinker has the same N-blind­ness as Scott him­self :-).

• gjm 10 Feb 2020 3:07 UTC

  7 points

  in reply to: Benquo's comment on: REVISED: A drown­ing child is hard to find

  Could you give an ex­am­ple or two? I don’t mean of one per­son as­sum­ing shal­low diminish­ing re­turns and an­other as­sum­ing steep diminish­ing re­turns—ob­vi­ously differ­ent peo­ple may have differ­ent opinions—but of a sin­gle per­son do­ing the sort of com­bi­na­tion you de­scribe.

  The ac­tual ar­ti­cle doesn’t, so far as I can see, at all fo­cus on any such cases; it doesn’t say “look, here are some bo­gus ar­gu­ments peo­ple make that as­sume two differ­ent in­com­pat­i­ble things”; rather, it says “EA or­ga­ni­za­tions say you should give money to EA causes be­cause that way you can do a lot of good per unit money, but they are ly­ing to you and you should do other things with your money in­stead”. (Not an ac­tual quo­ta­tion, of course, but I think a fair para­phrase.)

  So I don’t un­der­stand how your defence here makes any sense as a defence of the ac­tual ar­ti­cle.

  A cou­ple of other points, while I have your at­ten­tion.

  ----

  The ar­ti­cle says this:

  My former em­ployer GiveWell in par­tic­u­lar stands out, since it pub­lishes such cost-per-life-saved num­bers, and yet recom­mended to Good Ven­tures that it not fully fund GiveWell’s top char­i­ties; they were wor­ried that Good Ven­tures would be sav­ing more than their “fair share” of lives.

  All credit to you, once again, for link­ing to what GiveWell ac­tu­ally wrote. But … it seems to me that, while in­deed they did use the words “fair share”, your de­scrip­tion of their rea­sons doesn’t at all match what they say. Let me quote from it:

  Over the past cou­ple of weeks, we’ve had many in­ter­nal dis­cus­sions about how to rec­on­cile the goals of (a) recom­mend­ing as much giv­ing as pos­si­ble from Good Ven­tures to top char­i­ties, which we con­sider out­stand­ing giv­ing op­por­tu­ni­ties; (b) pre­serv­ing long-run in­cen­tives for in­di­vi­d­u­als to sup­port these char­i­ties as well. The pro­pos­als that have come up mostly fit into one of three broad cat­e­gories:

  … and then the three cat­e­gories are “fung­ing”, “match­ing”, and “split­ting”, and it’s in ex­plain­ing what they mean by “split­ting” that they use the words “fair share”. But the goal here, as they say it, is not at all to have ev­ery­one save a “fair share” of lives. They give some rea­sons for favour­ing “split­ting” (ten­ta­tively and cor­rigibly) and those rea­sons have noth­ing to do with “fair shares”. Also, they never, btw, talk about a fair share of lives saved but of fund­ing pro­vided, and while of course those things are closely con­nected they are not in­ten­sion­ally equiv­a­lent and there is an enor­mous differ­ence be­tween “we favour an ap­proach that can be sum­ma­rized as ‘donors con­sider the land­scape of donors and try to es­ti­mate their share of the fund­ing gap, and give that much’” and “it would be bad if any­one saved more than their fair share of lives”.

  Could you ex­plain why you chose to de­scribe GiveWell’s po­si­tion by say­ing ‘they were wor­ried that Good Ven­tures would be sav­ing more than their “fair share” of lives’? Do you ac­tu­ally think that is an ac­cu­rate de­scrip­tion of GiveWell’s po­si­tion?

  ----

  A key step in your ar­gu­ment—though it seems like it’s sim­ply taken the place of other en­tirely differ­ent key steps, with the ex­act same con­clu­sion allegedly fol­low­ing from it, which as I men­tioned above seems rather fishy—goes like this. “If one could do a great deal of good as effi­ciently as the num­bers com­monly thrown about im­ply, then it would be pos­si­ble to run an ex­per­i­ment that would ver­ify the effec­tive­ness of the in­ter­ven­tions, by e.g. com­pletely elimi­nat­ing malaria in one coun­try. No one is run­ning such an ex­per­i­ment, which shows that they re­ally know those num­bers aren’t real. On the other hand, if there’s only a small­ish amount of such good to be done that effi­ciently, then EA or­ga­ni­za­tions should be spend­ing all their money on do­ing it, in­stead of what­ever else they’re do­ing. But they aren’t, which again shows that they re­ally know those num­bers aren’t real. Either way, what they say is dishon­est PR and you should do some­thing else with your money.”

  It looks to me as if ba­si­cally ev­ery step in this ar­gu­ment is wrong. Maybe this is be­cause I’m mi­s­un­der­stand­ing what you’re say­ing, or failing to see how the logic works. Let me lay out the things that look wrong to me; per­haps you can clar­ify.

  • The “great deal of good” branch: run­ning ex­per­i­ments.

    • It doesn’t at all fol­low from “there is an enor­mous amount of good to be done at a rate of $5k per life-equiv­a­lent” that there are nice con­clu­sive ex­per­i­ments like re­duc­ing malaria deaths to zero in one coun­try for one year and mea­sur­ing the cost. Many malaria deaths in a given year may be from in­fec­tions in ear­lier years; even if a large frac­tion of malaria can be pre­vented at $5k per life-equiv­a­lent, the marginal cost will surely in­crease a lot as you get to the hard­est cases; elimi­nat­ing all malaria deaths some­here will prob­a­bly re­quire mul­ti­ple differ­ent kinds of in­ter­ven­tion, and any given or­ga­ni­za­tion has ex­per­tise only in a sub­set of them, and co­or­di­na­tion is hard.

    • You might want (gen­uinely, or for rhetor­i­cal pur­poses, or both) EA char­i­ties’ money to be spent on run­ning nice con­clu­sive ex­per­i­ments, but that is no guaran­tee that that’s ac­tu­ally the most effec­tive thing for them to be do­ing.

    • Still less is it a guaran­tee that they will see that it is. (It could be that run­ning such an ex­per­i­ment is the best thing they could do be­cause it would con­vince lots of peo­ple and open the floodgates for lots of dona­tions, but that for one rea­son or an­other they don’t re­al­ise this.) So even if (1) there are nice con­clu­sive ex­per­i­ments they could run and (2) that would ac­tu­ally be the best use of their money, that’s not enough to get from “they aren’t run­ning the ex­per­i­ments” to “they know the re­sults would be bad” or any­thing like that. They might just have an in­ac­cu­rate model of what the con­se­quences of the ex­per­i­ments would be. But, for the avoidance of doubt, I think #1 and #2 are both ex­tremely doubt­ful too.

    • It’s not perfectly clear to me who is sup­posed to be run­ning these ex­per­i­ments. In or­der to get to your con­clu­sion that EA or­ga­ni­za­tions like GiveWell are dishon­est, it needs to be those or­ga­ni­za­tions that could run them but don’t. But … I don’t think that’s how it works? GiveWell doesn’t have any ex­per­tise in run­ning malaria-net ex­per­i­ments. An or­ga­ni­za­tion like AMF could maybe run them (but see above: most likely it would ac­tu­ally take lots of differ­ent or­ga­ni­za­tions work­ing to­gether to get the sort of clear-cut an­swers you want) but it isn’t AMF that’s mak­ing the cost-per-life-equiv­a­lent claims you ob­ject to, and GiveWell doesn’t have the power to force AMF to burn a large frac­tion of its re­sources on run­ning an ex­per­i­ment that (for what­ever rea­son) it doesn’t see as the best use of those re­sources. (You men­tion the Gates Foun­da­tion as well, but they don’t seem ac­tu­ally rele­vant here.)

  • The “small­ish amount of good” branch: what fol­lows?

    • If I un­der­stand your ar­gu­ment here cor­rectly (which I may well not; for what­ever rea­son, I find all your com­ments on this point hard to un­der­stand), you reckon that if there’s (say) $100M worth of $5k-per-life-equiv­a­lent good to do, then GiveWell should just get Good Ven­tures to do it and move on.

    • As you know, they have given some rea­sons for not do­ing that (the rea­sons I think you mischar­ac­ter­ized in terms of ‘sav­ing more than their “fair share” of lives’).

    • I think your po­si­tion is: what they’re do­ing is de­liber­ately not sav­ing lives in or­der to keep hav­ing an at­trac­tive $5k-per-life-equiv­a­lent figure to dan­gle in front of donors, which means that if you give $5k in the hope of do­ing one life-equiv­a­lent of good then you’re likely ac­tu­ally just re­duc­ing the amount GiveWell will get Good Ven­tures to con­tribute by $5k, so even if the marginal cost re­ally is $5k per life-equiv­a­lent then you aren’t ac­tu­ally get­ting that life-equiv­a­lent be­cause of GiveWell’s poli­cies. (I’m not at all sure I’m un­der­stand­ing you right on this point, though.)

      • Whether or not it’s your po­si­tion, I think it’s a wrong po­si­tion un­less what GiveWell have said about this is out­right lies. When dis­cussing the “split­ting” ap­proach they end up prefer­ring, they say this: ‘But they [sc. in­cen­tives for in­di­vi­d­ual donors] are neu­tral, pro­vided that the “fair share” is cho­sen in a prin­ci­pled way rather than as a re­sponse to the pro­jected be­hav­ior of the other fun­der.’ (Em­pha­sis mine.) And: ‘we’ve cho­sen 50% largely be­cause we don’t want to en­g­ineer – or ap­pear to be en­g­ineer­ing – the figure around how much we pro­ject that in­di­vi­d­u­als will give this year (which would cre­ate the prob­le­matic in­cen­tives as­so­ci­ated with “fung­ing” ap­proaches).’

    • In­ci­den­tally, they also say this: ‘For the high­est-value giv­ing op­por­tu­ni­ties, we want to recom­mend that Good Ven­tures funds 100%. It is more im­por­tant to us to en­sure these op­por­tu­ni­ties are funded than to set in­cen­tives ap­pro­pri­ately.’ So for those “high­est-value” cases, at least, they are do­ing ex­actly what you com­plain they are not do­ing.

    • A sep­a­rate con­sid­er­a­tion: the most effec­tive things for a large or­ga­ni­za­tion to fund may not be the same things that are most effec­tive for in­di­vi­d­ual donors to fund. E.g., there may be long-term re­search pro­jects that only make sense if fu­ture sup­port is guaran­teed. I think the Gates Foun­da­tion does quite a bit of this sort of thing, which is an­other rea­son why I think you’re wrong to bring them in as (im­plic­itly) an ex­am­ple of an or­ga­ni­za­tion that ob­vi­ously would be giv­ing billions for malaria nets if they were re­ally as effec­tive as the likes of GiveWell say they are.

  • Sup­pose it turns out that the widely-touted figures for what it costs to do one life-equiv­a­lent of good are, in fact, some­what too low. Maybe the right figure is $15k/​life in­stead of $5k/​life, or some­thing like that. And sup­pose it turns out that GiveWell and similar or­ga­ni­za­tions know this and are pub­li­ciz­ing smaller num­bers be­cause they think it will pro­duce more dona­tions. Does it fol­low that we can’t do a lot of good with­out a bet­ter and more de­tailed model of the rele­vant bit of the world than we can re­al­is­ti­cally ob­tain, and that we should all aban­don EA and switch to “tak­ing care of your­self and your friends and the peo­ple around you and your com­mu­nity and try­ing spe­cific con­crete things that might have spe­cific con­crete benefits”? I don’t see that it does: to make EA a bad “in­vest­ment” it seems to me that it has to be much wronger than you’ve given any rea­son to think it is likely to be. (Jeff K has said some­thing similar in com­ments to the origi­nal ar­ti­cle, but you didn’t re­spond.)

• gjm 7 Feb 2020 13:37 UTC

  10 points

  in reply to: adamShimi's comment on: What Money Can­not Buy

  I’m pretty sure you’re wrong about the xkcd ex­am­ple.

  He doesn’t just look at the num­ber of char­ac­ters in the four words. He reck­ons 11 bits of en­tropy per word and doesn’t op­er­ate at the let­ter level at all. If those words were picked at ran­dom from a list of ~2000 words then the en­tropy es­ti­mate is cor­rect.

  I don’t know where he ac­tu­ally got those words from. Maybe he just pul­led them out of his head, in which case the effec­tive en­tropy might be higher or lower. To get a bit of a han­dle on this, I found some­thing on the in­ter­net that claims to be a list of the 2000ish most com­mon English words (the ac­tual figure is 2265, as it hap­pens) and

  • checked whether the xkcd words are in the list (“cor­rect” and “horse” are, “bat­tery” and “sta­ple” aren’t)

  • gen­er­ated some quadru­ples of ran­dom words from the list to see whether they feel stranger than the xkcd set (which, if true, would sug­gest that maybe he picked his by a pro­cess with less real en­tropy than pick­ing words at ran­dom from a set of 2000). I got: re­sult lie va­ri­ety work; fail pre­vi­ously any­thing weak­ness; ex­pe­rienced un­der­stand rel­a­tive effi­ciency; ear rec­og­nize list shower; class­room in­fla­tion space re­friger­a­tor. Th­ese feel to me about as strange as the xkcd set.

  So I’m pretty will­ing to be­lieve that the xkcd words re­ally do have ~11 in­de­pen­dent bits of en­tropy each.

  In your lo­cal com­mu­nity’s pro­ce­dure, I worry about “find­ing a very long sen­tence”. Mak­ing it up, or find­ing it some­where else? The to­tal num­ber of sen­tences in already-ex­ist­ing English text is prob­a­bly quite a lot less than 2^44, and I bet there isn’t that much en­tropy in your choice of which let­ter to pick from each word.

• gjm 7 Feb 2020 13:25 UTC

  2 points

  on: Pair Ra­tion­al­ity—the Pre­de­ces­sor to Group Rationality

  This seems to have been chopped off rather early. Is it a draft ac­ci­den­tally re­leased into the wild?

• gjm 7 Feb 2020 13:14 UTC

  4 points

  on: More write­ups!

  “Hex­ing the tech­ni­cal in­ter­view” is hilar­i­ous but I wouldn’t re­ally clas­sify it as “I did X, and here’s how it went”.

  (I hope.)

• gjm 6 Feb 2020 10:03 UTC

  10 points

  on: Open & Wel­come Thread—Fe­bru­ary 2020

  Steven Pinker is run­ning a gen­eral-ed­u­ca­tion course on ra­tio­nal­ity at Har­vard Univer­sity. There are some in­ter­est­ing peo­ple booked as guest lec­tur­ers. De­tails on Pinker’s web­site, in­clud­ing links that will get you to video of all the lec­tures (there have been three so far).

  I’ve watched only the first, which sug­gests un­sur­pris­ingly that a lot of the ma­te­rial will be fa­mil­iar to LW reg­u­lars.

• gjm 4 Feb 2020 20:59 UTC

  8 points

  on: Open & Wel­come Thread—Fe­bru­ary 2020

  Google’s AI folks have made a new chat­bot us­ing a trans­former-based ar­chi­tec­ture (but a net­work sub­stan­tially big­ger than full-size GPT2). Blog post; pa­per on arXiv. They claim it does much bet­ter than the state of the art (though I think ev­ery­one would agree that the state of the art is rather unim­pres­sive) ac­cord­ing to a hu­man-eval­u­ated met­ric they made up called “sen­si­ble­ness and speci­fic­ity av­er­age”, which means pretty much what you think it does, and ap­par­ently cor­re­lates with per­plex­ity in the right sort of way.