I'm guessing someone had a hunch and wanted to buy some HEPA filters. Also, all HEPA filters should filter air similarly, the price should be based on the rate at which air is filtered. I bought a HEPA air filter for $150 for my room.
>For a sense of scale, Mathematica Policy Research’s best evidence on the effectiveness of the highly touted KIPP charter school network finds that after three years at KIPP there is significant improvement on three out of four test metrics — up 0.25 standard deviations on one English test, 0.22 standard deviations on another, and 0.28 standard deviations on one of two math tests.
I wasn't sure what .22 std deviations meant, so I looked stuff up a bit. For a normal distribution, going from the average to 1 standard deviation above is going from the 50th percentile to the 84th percentile. Going up .22 standard deviations from the average is going from the 50th percentile to about the 55th percentile.
I was reading about the Order of Cistercians the other day, and I am reminded of this passage from wikipedia:
Relaxations were gradually introduced into Cistercian life with regard to diet and simplicity of life. Also, they began accepting the traditional sources of income that monks in comparable orders used: like rents, tolls, and benefices. The agricultural operations were blessed by success. Wealth and splendour characterized the monasteries, so that by 1300, the standard of living in most abbeys was comparable, if not higher, than the standards middling nobles enjoyed.[59]
[59] Jaritz, Gerhard (1985). "The Standard of Living in German and Austrian Cistercian Monasteries of the Late Middle Ages". In Elder, E. Rozanne (ed.). Goad and Nail. Studies in medieval Cistercian history. Kalamazoo, Michigan: Cistercian Publications. p. 57. ISBN 978-0-87907-984-0. "A study [Watzl 1978] done for the Lower-Austrian abbey of Heiligenkreuz demonstrates that in the first half of the fifteenth century, no fewer than 201-207 days of the year saw extra food."
One documentary I watched claimed that they tend to accumulate significant wealth so much so that their effects can be seen on the communities that surround them.
There are probably a lot of reasons for this. Much of the profit from the work done by the monks is often captured by the institution and used to purchase land and buildings. Large monasteries might have dozens or even hundreds of able bodied men engaged in light agriculture, bee keeping, beer production, etc. and that adds up over decades and centuries.
I think when we consider productivity you might be thinking of Silicon Valley hustle culture rather than the effect a community has over centuries.
If that data is submitted by individuals to a particular company, is it possible to see a lot more detailed heatmap, perhaps down to each address of each company?
And - of course - you're probably not even paying a couple of cents less. Those couple of cents are extra profit for everyone further up the 'value chain'.
And yet you would get, on average, 0 microplastics from drinking out of plastic bottles since those are brand new bottles which have not been subject to UV degradation of any kind. They're also entering via the GI tract, which doesn't have a particularly high rate of foreign matter exchange with the blood stream.
Meanwhile you'll walk outside sipping your glass bottle and take a deep breath of tire dust from nearby cars, which is actually the primary route of exposure for microplastics to enter the body since the lungs do exchange particles with the blood stream (notably, you will also find silicates, soot and basically every other type of thing all throughout the body via lung exchange as a mechanism).
