But you will never guess that the latest tik-tok craze will last another 50 years, and you'll never guess that Saturday Night Live (which premiered in 1075) will end 5-minutes from now. Your guesses are thus more likely to be accurate than if you ignored the information about how long something has lasted so far.
Sure, but the opposite also applies. If in 1969 you guessed that the wall would last another 20 years, then in 1989, you'll guess that the wall of Berlin will last another 40 years - when in fact it was about to fall. And in 1949, when the wall was a few months old, you'll guess that it will last for a few months at most.
So no, you're not very likely to be right at all. Now sure, if you guess "50 years" for every event, your average error rate will be even worse, across all possible events. But it is absolutely not true that it's more likely that SNL will last for another 50 years as it is that it will last for another 10 years. They are all exactly as likely, given the information we have today.
If I understand the original theory, we can work out the math with a little more detail... (For clarity, the berlin wall was erected in 1961.)
- In 1969 (8 years after the wall was erected): You'd calculate that there's a 50% chance that the wall will fall between 1972 (8x4/3=11 years) and 1993 (8x4=32 years)
- In 1989 (28 years after the wall was erected): You'd calculate that there's a 50% chance that the wall will fall between 1998 (28x4/3=37 years) and 2073 (28x4=112 years)
- In 1961 (when the wall was, say, 6 months old): You'd calculate that there's a 50% chance that the wall will fall between 1961 (0.5x4/3=0.667 years) and 1963 (0.5x4=2 years)
I found doing the math helped to point out how wide of a range the estimate provides. And 50% of the times you use this estimation method; your estimate will correctly be within this estimated range. It's also worth pointing out that, if your visit was at a random moment between 1961 and 1989, there's only a 3.6% chance that you visited in the final year of its 28 year span, and 1.8% chance that you visited in the first 6 months.
> Well, there’s nothing special about the timing of my visit. I’m just travelling—you know, Europe on five dollars a day—and I’m observing the Wall because it happens to be here.
It's relatively unlikely that you'd visit the Berlin Wall shortly after it's erected or shortly before it falls, and quite likely that you'd visit it somewhere in the middle.
No, it's exactly as likely that I'll visit it at any one time in its lifetime. Sure, if we divide its lifetime into 4 quadrants, its more likely I'm in quadrant 2-3 than in either of 1 or 4. But this is slight of hand: it's still exactly as likely that I'm in quadrant 2-3 than in quadrant (1 or 4) - or, in other words, it's as likely I'm at one of the ends of the lifetime as it is that I am in the middle.
I haven’t heard that statistic before. And the formulation seems imprecise? Does continuously beating the market mean that every single minute your portfolio value gains relative to the market?
I didn't realize "Juneteenth" was considered "Black-sounding" by some people. Juneteenth is a pretty culturally mainstream term (being a national holiday). And forming new words using contractions doesn't seem like a typically Black-person thing to do.
I associate the term with Black people, not because of how it sounds, but because I know what it means and know about it's origin among formerly-enslaved Black communities.
Maybe you mainly heard it said by black people, so it just sounds black to you? Whereas someone who heard about it on Twitter in 2015 wouldn't have made the same subconscious association, even if it's explicitly about celebrating freeing black people from slavery.
Oh, no. It sounds black because it is black. Check the history. "Juneteenth" the term was absolutely invented by black folks. I'm just finding it interesting that it "doesn't sound black to others."
I mean, I know that. I'm thinking of why it doesn't "sound black" to others but it does to you. Words are just words. They don't have inherent qualities that can't change or are the same to those who haven't heard the word before.
Yeah, I mean I know this can be a feather-ruffling point but (esp at my age) there's something wild about the Black slang -> "mainstream cool" slang pipeline that's ubiquitous and feels instant. :)
Author here. @sokoloff also pointed this out in their comment. You are right, the example confuses by making the group sizes different.
I will update the article so it reads like this:
Ten wealthy art patrons each contribute €1,000,000 to the local public art museum.
Total Contributions: 10×€1,000,000=€10,000,000
QF allocates: (10×sqrt(1,000,000))²=€100,000,000
Subsidy: €90,000,000
Ten lower‑income individuals each contribute €100 to replace lead pipes in their neighborhood
Total Contributions: 10×€100=€1,000
QF allocates: (10×sqrt(100))²=€10,000
Subsidy: €9,000.
Here, both groups get their contributions multiplied 10x. But the high-income group gets 10,000x the subsidy.
Given the assumption of wealth equality (and other assumptions), the QF paper proves that allocating more money to art maximizes social welfare, because if people contribute more to the art, it means art it has more utility.
But given the reality of wealth inequality, and the theory of diminishing marginal utility of wealth, the wealthy may contribute more to art simply because they can afford it, and because 1,000,000 may not have any more utility to them than 100 has to a very poor person.
"the example confuses by making the group sizes different"
But isn't that also realistic, since there a lot more people with little income and "small" problems than ultra-wealthy potential art patrons?
Today, if I get 1000 people to give $10 to the local library or public sport place, I have $10.000.
(1000xsqrt(10))² are $10.000.000.
For me, an obvious fix for potential exploitation would be to cap the individual contribution to 10k or 100k.
However, as I said I know nothing about qf and this has prob. already been discussed to death.
The authors of the QF paper describe it as "an extension of the logic of quadratic voting." They involve similar formulas and both are theoretically optimal (or efficient), and have a single equilibrium. These properties are proven using somewhat similar math.
But they apply to quite different settings and are not really the same thing. With Quadratic Voting, people pay for votes (with cost determined by a certain formula). With Quadratic Funding, people contribute to projects (with matching funds determined by a certain formula).
QV also makes many assumptions that rarely hold in reality, just like QF does. I may write an article about this someday.
What straw man? The assumptions underlying the theory of QF are spelled out cleanly in the original QF paper. The article is just enumerating these assumptions and showing they don't hold in reality.
The numbers in the example are indeed impossible to measure. But QF is claiming *optimality* -- that it maximizes social welfare -- when certain assumptions hold. To show that QF does not maximize social welfare when these assumptions don't hold, it suffices to show a single hypothetical counterexample.
I don't hold any cards in the game - if QF is bollocks, so be it, I couldn't care less.
The reasons why I've commented are:
1) the article does a really bad job at using words that matter to me, like "utility". If any theory – QF or OPs own line of thought – tells me that funding cancer research doesn't have utility for the person funding it, that theory is BS. I don't need a badly made up hypothetical counterexample for this.
2) The author contradicts themselves: "QF assumes that all utility is direct utility, benefiting the contributor only." – but then they go on and calculate the utility of spending money on saving lives not based on the utility of the contributors, because "that’s not the kind of utility we’re trying to maximize" (btw, who is "we"!?), but based on some arbitrary made-up value and number of saved lives.
Actually, everything you complain about is highly irrelevant. It can't be overstated how irrelevant your objection is.
> (other than feeling good about those lives being saved, but that’s not the kind of utility we’re trying to maximize).
Your interpretation of this statement is that the contributors have a fixed marginal utility for every single dollar, so that they will consider the situation where they spend $1,000,000 per live saved to be superior to the situation where they spend $100,000. In other words, you're saying that welfare is a veblen good for the donor.
The author makes the argument that the mere act of spending more money to save lives is not the type of utility we should strive for to maximize social welfare.
Your utility in question is not about feeling good about saving people regardless of cost, it's about feeling good about saving people, precisely because it costs money and you personally spent money to do it.
By the way, why is that "your utility"? Why am I putting words in your mouth? Because you're disagreeing with the author and therefore necessarily put yourself at odds with the authors objection to the first interpretation. Hence you must necessarily agree with it, otherwise you're just trolling and that would be uncharitable of me to accuse you of. So, yes, you must have mistakenly chosen the silly interpretation.
I think I disagree with nkmnz' specifics. But I'm not sure! It's possible I might agree with nkmnz across the board.
This might be a case where someone familiar with the subject could follow what you're saying just fine, but most of us HN commenters don't know enough about the subject to get it. That can happen here (e.g. on physics topics). In any case I can't really follow your arguments closely.
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