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Houston is experiencing its third ‘500-year’ flood in 3 years

washingtonpost.com

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Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#141

Post by Mz »

HillaryBriss wrote: post #136
Mz wrote: post #131

Earlier quoted context omitted.

I have said that repeatedly on HN. Obamacare is a terrible idea and we need another solution.

well. ok. but, i don't see placing the blame on Obamacare. i mean that was not the origin of the concept of health insurance.

Yes, but health insurance worked differently before Obamacare. Insurance companies simply did not cover chronically ill people or people with preexisting conditions, thus they were able to arrange a "bet." Obamacare removes the element of a "bet" from the system.

Just like the government provides fire protection in the form of fire departments, the government needs to provide health care. What we are doing currently is broken.

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#142

Post by Mz »

stale2002 wrote: post #137
CamperBob2 wrote: post #130

Earlier quoted context omitted.

That's a fool's bet to say "I will pay you X amount of money if it floods" when it is guaranteed to flood sooner or later. That amounts to charity, not insurance. A statement with profound implications in other areas of insurance, notably health insurance. You're insuring against expensive losses that will almost certainly happen at some point... which suggests that traditional insurance isn't the right framework for…

Huh? Why? Just charge more money for your insurance. Boom! Profitable business.

The people who most need healthcare tend to have low incomes because they are chronically ill. So, no, that Boom! fundamentally does not work.

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#143

Post by interstitial »

blondie9x wrote: post #110
ars wrote: post #79

Earlier quoted context omitted.

I know it's easy to blame climate change for anything and everything, but that's simply incorrect. The actual takeaway is that our data is wrong, these floods occur more often than we thought. With only 150 years of good data, it's impossible to calculate "500 year" events accurately. You would need around 5,000 years of data to do that, and we don't have it. So we ended up significantly underestimating how often the…

You can see in graph that floods are occurring more often and that clouds are able to absorb more water as temperatures rise. This hurricane would have happened. But this flooding is worsening because of climate change that is irrefutable.

By irrefutable, what do you mean? Over-fitting and variance should make normal engineers more cautious. Evidently, climate science is far more magical.

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#144

Post by hexane360 »

learc83 wrote: post #62
hexane360 wrote: post #43

Earlier quoted context omitted.

Birthday paradox relies on non-independent events. I'd assume floods should be relatively independent between different cities, meaning that the number of 500-year flood events in the U.S. would follow a binomial distribution ( https://en.wikipedia.org/wiki/Binomial_distribution ). p = 1/500 years = 0.002 For 100 cities, the probability of at least one city having a 500-year flood is 18.14%. For a 3-year run: p = (1/…

How does the birthday paradox rely on non-independent events?

I guess what I meant wasn't "non-independent events". However, there is still a fundamental difference. The probability of a 500-year flood happening next year is still 0.2%. With a birthday paradox, the filling of birthdays is what causes the explosion in probability. Assuming no collisions so far, the 20th person you add to the room has a 19/365 chance of colliding, while the 2nd person only has a 1/365 chance.

I'm not sure how to succinctly phrase this idea. Maybe "non-constant probabilities"?

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#145

Post by interstitial »

ars wrote: post #79
blondie9x wrote: post #61

The fundamental takeaway from this article is about half way down. Major flood events are occurint more frequently. What was once likely to hit a city every 500 years is happening to more cities on a planetary scale more frequently.

I know it's easy to blame climate change for anything and everything, but that's simply incorrect. The actual takeaway is that our data is wrong, these floods occur more often than we thought. With only 150 years of good data, it's impossible to calculate "500 year" events accurately. You would need around 5,000 years of data to do that, and we don't have it. So we ended up significantly underestimating how often the…

It's almost like you are saying the model was overfit to the data.

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#146

Post by kbenson »

curiouscats wrote: post #11
bkohlmann wrote: post #2

While the article obliquely makes reference to this, I wonder if this is somewhat similar to the "birthday" problem in statistics. Any given person has ~1 in 365 chance of being born on a particular day. Yet, if you have 30 people in a room, there is a greater than 50 percent chance that at least one PAIR has the same birthday. Given the hundreds of cities (thousands?) in the US that may be affected by a flood, it's…

A 500 year flood event is very likely new data that tells us our prediction it was a 1 in 500 year event was wrong. http://engineering.curiouscatblog.net/2008/07/13/500-year-floods/ It is of course possible, it was actually a once in 500 year event. I just believe it is much more likely our previous conclusion was faulty. Our prediction of 500 year floods is not very good, we rely on way less than 500 years of data.…

> It is of course possible, it was actually a once in 500 year event. I just believe it is much more likely our previous conclusion was faulty.

It seems it could go either way to me, and the way to get a good indication of which is most likely is to look at look at much smaller timeframe models and assess if they are changing over time, and how much. It's entirely possible it's both, but it seems we have a good way of gauging the relative importance of changing climate norms so we should at look at that before discounting it as noise in the bigger problem of poor models in general.

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#147

Post by curiousgeorgio »

bkohlmann wrote: post #2

While the article obliquely makes reference to this, I wonder if this is somewhat similar to the "birthday" problem in statistics. Any given person has ~1 in 365 chance of being born on a particular day. Yet, if you have 30 people in a room, there is a greater than 50 percent chance that at least one PAIR has the same birthday. Given the hundreds of cities (thousands?) in the US that may be affected by a flood, it's…

A more accurate term for what you describe would be a clustering illusion[1], and it certainly could be a valid explanation (among other possibilities) for the observation made in the article.

[1] https://en.wikipedia.org/wiki/Clustering_illusion

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#148

Post by emeraldd »

HillaryBriss wrote: post #135
Retric wrote: post #115

Earlier quoted context omitted.

That's not the problem. Private insurance does not offer flood insurance because A) it tends to all be due at the same time requiring a very large fund. B) It also promotes people living in flood prone areas. C) It's very hard to asses risks. Combined and you end up with bankrupt insurance companies. The industry also feels B makes selling flood insurance a bad idea. That said, there are Private policies you can buy…

> it tends to all be due at the same time requiring a very large fund. i don't quite see that. if the flood insurer covered a broad variety of geographically dispersed areas across North America, or even just the US, would that be true?

The company would have to be huge to pull it off. One event like what happened in Houston could easily wipe out a big chunk of any fund they could amass. That kind of diversity could also be a problem if there are shared waterways, think back to the Mississippi/Missouri flood from 1993. I'm seeing 15 billion as the damages there, which is a large percentage of the "cash" pile Apple is claimed to have.

https://en.m.wikipedia.org/wiki/Great_Flood_of_1993

Edit: fix an extraneous wording mistake.

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#149

Post by gnaritas »

Mz wrote: post #140
gnaritas wrote: post #138

Earlier quoted context omitted.

Obamacare is not a terrible idea, it's a transitional idea as we're already doing this with insurance; it's an evolution of the system in the right direction, it's not a final solution. Add a national exchange, offer a public option, bam medicade for all.

bam medicade for all. That is called single payer, government provided coverage. I would support that. That is not remotely what Obamacare does. Obamacare requires private insurance to cover people with pre-existing conditions and it requires everyone to buy private insurance. It is busted as all fuck and I would like to see it go die in a fire. I am aware what we were doing before Obamacare sucks and we need a real…

Of course it's not what Obamacare does, you can't go from a private insurance market to a single payer government system in one single step. Obamacare is the transition between the two.

> Obamacare requires private insurance to cover people with pre-existing conditions and it requires everyone to buy private insurance.

So does single payer, we just call "buying" taxes and we replace insurers with government. You're still forced to pay and the insurer is still forced to provide for everyone regardless of pre-existing conditions. So it would seem you're simply against the name Obamacare.

> But this is not a real solution.

It's not supposed to be, everyone isn't blind, they see that single payer is the solution, but you can't simply declare the private insurance industry we already have dead in one fell swoop. Obamacare or something just like Obamacare is a necessary step to get to single payer. We need to get everyone into a public option, and then have that option slowly kill off private insurance by simply operating cheaper than they can until the public option is pretty much what is insuring everyone, at that point, it's effectively single payer.

Re: Houston is experiencing its third ‘500-year’ flood in 3 years

#150

Post by dogruck »

tuna-piano wrote: post #134
MarkMc wrote: post #95

The problem is that the person who judges the probability at 1-in-500 doesn't have any skin in the game. The judgement of the US meteorological office affects where people can build houses and how much they pay for government insurance. Homeowners have a strong financial interest in underestimating the probability of a severe flood, so there is likely subtle political pressure applied to the met office assessments. F…

And the reinsurance folks seem to say that there is absolutely no evidence that there has been an uptick in these big disastrous storms. People are constantly thinking of global warming, so when they see a storm, they say "Aha! Global Warming!". Of course there have always been hurricanes, and human perception/remembering is not a replacement for statistics and math. From Warren Buffet (One of the largest insurers of…

Markets also did not collapse when Donny won. But, hey, what do markets know?
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