Live data from Hacker News

The cognitive costs of air pollution

patrickcollison.com

51–60 of 300 posts

Re: The cognitive costs of air pollution

#51

Earlier quoted context omitted.

Pardon my ignorance, but how is this IQ data obtained? It is reported by the government? Are IQ tests standardized?

It's official data released by Chinese. Which helps explain why Han Chinese are on top of the list.

I don’t think that explains it. Especially when you compare results with other countries with a large Chinese population like Singapore, Malaysia, and Indonesia.

Re: The cognitive costs of air pollution

#52
post #28

Earlier quoted context omitted.

The South Coast (California) Air Quality Management District does some really thorough tests on the quality of the various low-cost sensors: https://www.aqmd.gov/aq-spec/evaluations/summary-pm

Anyone want to review this table and suggest a currently commercially available option in the $300 and lower price range? I may have time this afternoon but if anyone does go thorough it I'm interested to know.

Based on my reading of the table, the PurpleAir II sensors seemed to be the best of the sub $300 for PM1.0 (field R^2 of 0.96 to 0.98) and PM2.5 (field R^2 of 0.93 to 0.97). The PM10 readings were not as good (field R^2 of 0.66 to 0.70).

After skimming the rest of the table, it looks like the PurpleAir II sensors might have some of the best field R^2 for PM 2.5 and PM 1.0

Re: The cognitive costs of air pollution

#53

From the original source: > Stock market returns are lower on polluted days. I don't want to dismiss the entire article, but I think this points to possibility that there is some bad statistics going on here. I don't see how daily stock returns are proof of, or even related to, cognitive ability on a daily basis. This is exactly the type of finding you'd expect with p-hacking.

This is probably just a coincidence. Stock markets perform lower on Mondays: https://www.macroption.com/stock-market-performance-volatili... Traffic is probably generally higher on Mondays, though I have only anecdotal evidence.

Heh, a rare example of the "proof of correlation isn't proof of the absence of causation" fallacy. No reason that stock markets couldn't perform worse on Mondays because of the extra traffic pollution.

Re: The cognitive costs of air pollution

#54

From the original source: > Stock market returns are lower on polluted days. I don't want to dismiss the entire article, but I think this points to possibility that there is some bad statistics going on here. I don't see how daily stock returns are proof of, or even related to, cognitive ability on a daily basis. This is exactly the type of finding you'd expect with p-hacking.

Read the linked journal article; the authors don’t actually claim it is about cognitive ability, they attribute it to lower risk taking on those days.

Re: The cognitive costs of air pollution

#56

From the original source: > Stock market returns are lower on polluted days. I don't want to dismiss the entire article, but I think this points to possibility that there is some bad statistics going on here. I don't see how daily stock returns are proof of, or even related to, cognitive ability on a daily basis. This is exactly the type of finding you'd expect with p-hacking.

This is probably just a coincidence. Stock markets perform lower on Mondays: https://www.macroption.com/stock-market-performance-volatili... Traffic is probably generally higher on Mondays, though I have only anecdotal evidence.

The journal article explicitly calls out day of week and controls for it...

Re: The cognitive costs of air pollution

#57
post #41
post #12

Earlier quoted context omitted.

No that is not what it is claimed. Pollution reduces your IQ, not that it makes your IQ lower than someone else's. The people living in those cities form a so-called "self-selecting" sample. They are probably, on average better educated, and they recognize the value of education much better. They already would score higher than the others, that's why they moved to the city. It might just as well be that the same peop…

The original post doesn't mention IQ. IQ is a terrible metric for studying short-term cognitive effects.

IQ has a bad rap (rightfully so, thus no disagreement there). In the cited works they use tests that in the past were called IQ tests - though here all are called cognitive-scores.

Why wouldn't IQ tests be great for studying short term cognitive effects? I would trust their values for these type of studies the most: how does lack of sleep, being drunk, after exercise, etc affect your ability to solve abstract problems.

It has far fewer variables to account for than predicting someone's long term success.

Re: The cognitive costs of air pollution

#58
post #28

Earlier quoted context omitted.

The South Coast (California) Air Quality Management District does some really thorough tests on the quality of the various low-cost sensors: https://www.aqmd.gov/aq-spec/evaluations/summary-pm

Anyone want to review this table and suggest a currently commercially available option in the $300 and lower price range? I may have time this afternoon but if anyone does go thorough it I'm interested to know.

>*Field R2

Under the table is definition of R^2

>The coefficient of determination (R2) is a statistical parameter measuring the degree of relation between two variables. ....

The more - the better. Range [0; 1)

More device in your area === better quality of measurement

Re: The cognitive costs of air pollution

#59

This really bothers me. I live in a VERY polluted place, and unfortunately moving away won't be an option for me for at least half a decade. What can I do to minimise the health effects of such an atmosphere? I'm planning on getting an indoor air filter for my home.

I'm not sure what _VERY_ polluted means, but you might consider taking up more physical activity. On GCN youtube cycling channel they argued (including interviews with some health professionals) that even if you live in a city with considerable pollution, the positive effects of commuting on a bicycle outweigh the negative effects of air pollution. They were primarily talking about Britain-scale pollution of course. The principle might change if transfered to a more extreme environment. Something to look into.

Re: The cognitive costs of air pollution

#60

From the original source: > Stock market returns are lower on polluted days. I don't want to dismiss the entire article, but I think this points to possibility that there is some bad statistics going on here. I don't see how daily stock returns are proof of, or even related to, cognitive ability on a daily basis. This is exactly the type of finding you'd expect with p-hacking.

Maybe people are more negative because of traffic, noise and frustrated about getting to work later. I find it hard to imagine a way to control for this short of making people breathe these substances separately and seeing if they actually do have lower IQs. You can then control for the other factors. These all seem to be epidemiological studies that we can't show the pollution is for sure the root cause. It could, for example, be that pollution is 25% of the result for example with more noise, traffic, irritation etc. being the other 75%.
Post reply on HN