At the same time, consumers preempt their future inertia; 24%-36% of potential subscribers avoid subscribing when offered an auto-renewal promo. Further, offering an auto-renewal contract decreases the share of subscribers over the two years after the promo by 10%. Even though auto-renewal generates higher revenue in the medium-run due to payments from inert subscribers, auto-renewal and auto-cancel are revenue equivalent after one year, but with fewer subscribers in auto-renewal.
That doesn't surprise me. Yes, would be interesting to see those assumptions, but I guess the issue (as in most modelling of complex systems) is that as you relax the assumptions, the models become intractable.
I opened this article hoping it would mention the point about the rules concerning reduced sulfur content of the fuel used in super tanker marine shipping, and it didn't disappoint:
"A lot of people have looked at the impact of the marine shipping regulation change. If you take that and you put it into some climate model and you estimate the temperature change, right now you’d expect about 0.05 of a degree, 0.08 of a degree [of warming per year], and then building over a decade to about 0.1 degree. So that seems like it helps, but it doesn’t seem like it’s sufficient."
Based on the results of their modeling approach, cycling and high intensity interval training (HIIT) produced the most consistent effects in improvement of memory, attention, executive function, information processing and other cognitive functions.
"We found that vigorous activities had the largest effects," Giesbrecht said. "Also, the effects were strongest for studies that tested cognition after exercise, as opposed to during exercise. And lastly, the effects of exercise less than 30 minutes in duration were bigger than those that went beyond 30 minutes."
"Also among their findings, the team discovered that executive functioning was the key cognitive domain impacted by vigorous exercise, such as HIIT protocols."
It's probably true that not a lot of people make constructive use of their sleep data, but people just love learning about themselves: it's kind of a form of narcissism, unless you are experimenting with methods to shift the numbers some way. For my part, I use it for a lot of statistical tests.
Sometimes I like to think of GDP as a measure of economic (productive) power more than well-being. But other indicators are more important for the long-term, such as those on demographics, education, debt levels, etc. You probably don't want to sacrifice those for a transient boost in GDP.
On average, sleep/wake classification accuracies were reported to be 87.2% based on 53 assessed devices. There was no significant difference in accuracies between devices using only accelerometer data (86.7%, d = 28) and devices using both PPG and accelerometer data (87.8%, d = 22), as determined by a t-test (significance threshold p < 0.05). All reported accuracies ranged from 79% to 96%, except for Kanady et al.’s study28, which reported lower values of 54% and 64%. This difference can be attributed to their 24-hour measurement, which had a higher wake-to-sleep ratio compared to overnight measurements in other studies. Therefore, these accuracies reflect the generally poor performance of sleep classifiers in detecting wake. The average accuracy for 3-stage classification (wake vs. NREM vs. REM) was 69.7% (d = 3), and for 4-stage classification (wake vs. light vs. deep vs. REM), it was 65.2% (d = 9).
Quite good support for the caffeine/theanine interaction in the literature -- I was mainly trying to see if it could improve sleep which is why I didn't take it with caffeine. Would be interesting to do some blinded cognitive test at some point though to get some estimate on how much congitive performance is increased. I need to think about ways to measure that, aside from flashcards. I actually have the website connected to a chess API so that might be a nice test.
This is a good and fair question (although noting that the doses in the second study seem extremely large compared to supplement values). I think the solution is to test, test, and test on as many things as possible which is not being done at the moment. Most supplements will probably not have any notable effect, like L-theanine in my case, so a precautionary principle would lead one to discontinue use.
Good to hear they seem to be working out for you. I tried L-tryptophan a few years ago but discontinued rather quickly as I thought my sleep quality was going down (I think I was waking up during dreams more often). I guess 5-HTP would have been even more powerful.
Very interesting: maybe it could have been something else in the sodas? Alternatively, the quality of the amazon supplement might not have been great (unless you tried from multiple sources)
My view on this is if you don't find any effect or a tiny effect (the case here) that is already useful information. For most supplements, my bet is that you won't even benefit from a placebo effect.
And if you do find an effect, then you should do a more high-effort self-blinded test.
Another study: "According to Kaneko et al., the content of l-theanine in matcha tea infusions amounts to 6.1 mg/L [50], while Unno et al. [9] found as much as 44.65 mg/g of that compound in matcha tea samples." Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796401/
I'm not sure, but I guess one would use around 4 grams of matcha in a cup? So then at the upper bound you would come close to 200mg. But matcha has a lot of caffeine so probably not suitable to improve sleep.