←back to thread

190 points erwinmatijsen | 2 comments | | HN request time: 0.429s | source
Show context
arowthway ◴[] No.45113659[source]
This is super cool but the ending is bizarre.

> A comment on the YouTube video below complained, “Not a word about return on investment in the presentation. That means it’ll never pay off” MAGAlomaniacs are everywhere these days.

Given the supposed 50+ year lifespan of such a battery, I find it hard to believe it doesn't turn a profit at some point. And I understand that debunking low-effort accusations is asymmetric warfare. But why cite a random YouTube comment if you have no intention of addressing its claims? A more charitable interpretation is that it's meant to ragebait the readers. But to me, it seems like trying to make people feel ashamed for having doubts, by making a public example of a skeptic.

replies(12): >>45113894 #>>45113901 #>>45114039 #>>45114042 #>>45114328 #>>45114440 #>>45114465 #>>45114591 #>>45114612 #>>45114617 #>>45114754 #>>45115789 #
ta1243 ◴[] No.45113894[source]
People nowadays expect 10% return on their investment, so if you invest 1m you need to make 100k a year from it (120k to cover the deprecation over 50 years)

If you made 30k a year for 50 years you'd return 1.5m from your 1m investment, but you're only making 3%, which is a low return especially given the future risk (you'd have to run for 33 years just to get your initial investment back)

Either way it's worthwhile, because the reason people expect 10% is because the externalities are borne by others. Majority of people and countries in the world do not deem ROI to be the sole or even primary driver for investment, and judging investments only on the immediate financial reward already biases the conversation

replies(4): >>45113983 #>>45114006 #>>45114483 #>>45115118 #
kragen ◴[] No.45114483[source]
> Majority of people and countries in the world do not deem ROI to be the sole or even primary driver for investment

I think this is a little unfair. If it were true, it would be the reason for wealth inequality: you're saying that the majority of people and countries are so financially irresponsible that they consume any resources they get without investing any. But in fact everyone I have observed closely, in every socioeconomic group, tries to optimize ROI. Most of them aren't very good at it, but they do try.

On the other hand, people who expect a 10% risk-free return are just going to get scammed. There are 10% opportunities in most people's lives—weatherstripping, coupon clipping, bulk food buying, etc.—but you can run out pretty quickly.

replies(1): >>45114615 #
ta1243 ◴[] No.45114615[source]
> There are 10% opportunities in most people's lives

Average S&P total return (reinvesting dividends) is well over 10% over any appreciable timeframe (say 30 years), even during really low times (say buying at the peaks in 1999 or 1972)

replies(2): >>45114706 #>>45116495 #
zahlman ◴[] No.45114706[source]
The long term average is a bit over 10%, but there are definitely 30-year periods that have fared worse than that.
replies(1): >>45126128 #
1. ta1243 ◴[] No.45126128[source]
Which specific 30 year period?
replies(1): >>45132596 #
2. kragen ◴[] No.45132596[source]
If we restrict our attention to the cherry-picked-with-hindsight US stock market, the worst 30-year period would probably be 01929 to 01959, although 01903 to 01933 isn't that great either. The S&P 500 only goes back to 01957, but https://www.econstats.com/eqty/eq_d_na_4.csv shows the DJIA at US$382.01 on 01929-09-05. 30 years later, on 01959-09-04, it had reached US$653.91. That's 1.8% return per year, which is lower than 10%.

But wait! Those are nominal numbers, not inflation-adjusted numbers. And the dollar had lost nearly half its value over those 30 years! According to https://data.bls.gov/cgi-bin/cpicalc.pl?cost1=382.01&year1=1..., US$382.01 in September 01929 would be worth US$646.99 in September 01959. So the inflation-adjusted return was 0.035% per year. At least it's not negative! And that doesn't even include the dividends!

Nowhere close to competitive with insulating your house or bulk-buying food, though.