Posts

Comments

Comment by daniel-v on The US Already Has A Wealth Tax · 2020-08-21T15:38:45.103Z · score: 1 (1 votes) · LW · GW

^Not always true, but true often enough that it definitely bears mentioning.

If you invest in an asset that you expect to have a 0% real return and therefore hand you an after-tax real loss, and then you complain the tax system is handing you an after-tax real loss, there's something wrong there- is it with the tax system?

Comment by daniel-v on Criticism of some popular LW articles · 2020-07-20T15:00:04.914Z · score: 7 (4 votes) · LW · GW

To the contrary, I think the criticism of post 2 is very on point. But Zvi and I are looking at two different parts: Zvi's looking at the logic/begging the question part, and I'm looking at the critique. In thought experiments, we can take imagined exogenous changes to be exogenous even though in the real world they'd be endogenous (i.e., we can take them as events rather than outcomes). Later, we can relax that assumption; the endogeneity problem is important for understanding whether the conclusions extend to the real world, but it is not important for understanding what the conclusions are within the thought experiment. So I agree with Zvi that the logic isn't really an issue here.

However, I do believe this is a bad example (/weak post, Sorry Elizabeth) precisely for the reason AllAmericanBreakfast pointed out- it frames basic economics knowledge as a new insight. Admittedly, the EconLog post that was linked to doesn't discuss comparative advantage either, but that's because it's really just about the "flight to safety" in 2008 where capital has to go somewhere, so it goes to the safest haven- even if that place is on fire, at least it's not on fire next to a ticking time bomb. But, if you really want to talk about the "benefit not from absolute skill or value at a thing, but by being better at it than anyone else" then you can just consult microeconomics 101 (literally) and read up on absolute vs. comparative advantage. And then a better example of it is what you would find in the textbook (ha, probably Mankiw's) of English cloth vs. Portuguese wine, which clearly illustrates the concepts.

Or, maybe Elizabeth really wasn't referring to comparative advantage and more specifically to "when a superlative is applied in a context and the context is later lost." This might seemingly apply better to the USD (we think of it as a safe haven because we used to think of it as a safe haven), but again the USD is not an apt example here because the context isn't lost, it just changed (e.g., suppose the USD scores a 10/10 at being a currency and things change and now it's a terrible 3/10 but it's still better than all the rest). The Tallest Pygmy derives its tension from that fact that you think you've found someone "tall" but it's just among the pygmies you're sampling. The Tallest Pygmy, then, is best understood as getting stuck in a valley at a local, but not global, minimum (gradient descent). Or peaking at a local, but not global, maximum. Sometimes you are fine with local maxima, but if you are optimizing for global maxima, then obviously this creates a problem. May as well go with a classic example instead, which clearly illustrates sampling bias (statistics).

You see this in the academic literature as well where people refer to concepts as "effects." I think it is a good idea to be skeptical of those findings- not that they are fake, just that more clarity could be gained from understanding the core concept that generates the effect. Elizabeth's example is not great for comparative advantage, nor for gradient descent/sampling bias. The USD in 2008 is a "lesser of two evils effect," or really not an effect at all- if you have a choice between 10%, 9%, and 8% returns at equal risk, you choose 10%; if a regime change occurs that makes you choose between 5%, 4.5%, and 4%, you choose 5%. It's worse than before, but it's the best around.

LessWrong is a great community to be in, but AllAmericanBreakfast is correct that many posts stumble upon "new" insights that are really just symptomatic of not having done enough research, particularly when it comes to economics. And that's okay in this forum, we're all trying to figure this stuff out!

Comment by daniel-v on Can Covid-19 spread by surface transmission? · 2020-06-11T00:28:23.665Z · score: 5 (4 votes) · LW · GW

It can *survive* on surfaces for a long enough period of time for it to seem possible. But I think viral load is important and it might not practically be a serious vector for most people and most surfaces, particularly those that are commonly disinfected. It's amazing how our knowledge went from symptomatic/surface? to pre-symptomatic/aerosol? transmission.

Comment by daniel-v on How to validate research ideas? · 2020-06-05T13:15:15.770Z · score: 7 (2 votes) · LW · GW

Also a PhD here - read, read, read. You need to know what's been done to see what the gaps are and how your project would fit in. You will also build up that intuition.

Sure, it's also helpful to be able to bounce ideas around your network, but the less well-formed the idea is, the more likely it is to go to friends who aren't just going to shoot you down or for it to get the benefit of the doubt as "early-stage." You need to get the idea formed to the point where someone can feel comfortable pointing out issues, which will take independent research. You also see that here at LW, where ideas/points are usually more than a paragraph long.

Comment by daniel-v on How do you use face masks? · 2020-02-13T17:29:41.012Z · score: 4 (3 votes) · LW · GW

Here's a broader article with some pointers on masks.

Comment by daniel-v on Suspiciously balanced evidence · 2020-02-12T23:28:20.947Z · score: 1 (1 votes) · LW · GW

Good explanation #3- we perceive probabilities differently from their objective values (i.e., a question of calibration). Our responses to questions will be both a function of our "underlying" subjective probabilities and also the mapping of that to the response format. In the link, for example, responding with (p) 10% to 90% feels like being from (w(p)) 20% to 70% sure.

Comment by daniel-v on Using vector fields to visualise preferences and make them consistent · 2020-01-29T16:41:15.045Z · score: 1 (1 votes) · LW · GW

Charlie Steiner, right, it's not doable for, say, all products on (or could be on) the market, but it is certainly doable among the products in a person's consideration set. If we posit that they would make a choice among 4, then eliciting binary preferences might - but also might not - faithfully reflect how preferences look in the 4 set. So to MichaelA's point, if preferences are context-dependent, then you need to identify appropriate contexts, or reasonable situations.

Context-dependent preferences present a big problem because "true" context-less preferences...maybe don't exist. At the very least, we can make sure we're eliciting preferences in an ecologically-valid way.

Binary choices are useful, but when they lead to inconsistencies, one should wonder whether it's because preferences are inconsistent or whether it's an elicitation thing. If people really would choose between A and B and not consider C or D, then ranking A and B is the relevant question. If people would consider A, B, C, and D (or at least pick between A and B in the context of C and D) then ranking all four (or at least ranking A and B in the context of C and D) is the relevant question.

Comment by daniel-v on Using vector fields to visualise preferences and make them consistent · 2020-01-28T22:09:39.044Z · score: 5 (3 votes) · LW · GW

Very neat post.

Intransitive preferences can be found from a series of binary choices, but if you force a ranking among the full set, you won't have intransitive preferences (i.e., you can write out a gradient). This also means the elicitation procedure affects your inferences about the vectors. It would seem that circular preferences "fit," but really they could just be fitting the (preferences | elicitation method) rather than "unconditional" ("core" + "irrationality," whatever irrationality means) preferences. Preferences are also not independent of "irrelevant" alternatives as perceived attribute levels are evaluated contextually (that's necessarily irrational?).

One implication I see here is that 0 vectors are points with no inclination to switch or having "no desire." These would be useful model falsification points (e.g., Figure 7 implies that people don't care about sportiness at all conditional on weight being "right"). But they would also only seem to correspond to ideal points or "ideal configuration" points. Without data on what the agent wants and only on what they are being offered ("I want a sporty car, but not too sporty; Car A is closest, but still not quite right, too bad"), you'll be fitting the wrong hill to run up.

Comment by daniel-v on Applications of Economic Models to Physiology? · 2019-12-11T17:50:00.136Z · score: 4 (2 votes) · LW · GW

Related: Fungus arbitrage https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6584331/

What is the difference between a generic "signal" and a "price signal"? What is a "price" in physiology? I think it would be interesting to see what insights an economic perspective of physiology would provide, but the constructs need to be defined pretty clearly so analogies can be drawn.

Another question is which basic assumptions embraced in economics can reasonably apply to the units of analysis in physiology (cells, etc.). Economists already have a hard enough time validating assumptions for humans.

Comment by daniel-v on Randomness vs. Ignorance · 2019-11-08T02:53:21.093Z · score: 4 (4 votes) · LW · GW

This is aleatory (inherent randomness) vs. epistemic (knowledge) uncertainty. You can parse this as uncertainty inherent in the parameters vs. uncertainty inherent in your estimates of the parameters / the parameterization of the model.

This is a very important distinction that has received treatment in the prediction literature but, indeed, is not applied enough to interpreting others' predictions among laypeople.