२० ऑगस्ट, २०२०

"Harris saying 'inflection point' seems like kind of a call-out to FiveThirtyEight readers, to be honest."

"We’re still waiting for the first vice presidential nominee who says 'regression analysis' on stage though."

Said Nate Silver at 11:03 PM in the FiveThirtyEight live-blog of the Democratic Party Convention last night.

A reader sent me there, because I too reacted strongly — though quite differently — to Kamala Harris's use of the phrase "inflection point." I'd seen a lot of news sites pulling that quote and, like Silver, pleased with it. But here's what I blogged at 7:55 this morning:
I'd like to see person-in-the-street interviews testing whether people even understand what it means to say we're at an "inflection point." I don't think I've ever used the phrase "inflection point" on this blog...  The literal meaning of "inflection" is bending. America is at the point where we are bending? But what is a bending "point"? I've heard of the breaking point. And one often speaks of bending as something that is done to avoid breaking. If we're bendable — and perhaps therefore not breakable — aren't we always bending? Is there some particular place for bending, and why is it now? Why are we at "an inflection point"? I have to infer that it means that we're at a point where if we stand rigid, we risk breaking. The next phrase is "The constant chaos leaves us adrift." We're "adrift" and "afraid" and "alone." And therefore it is time to bend....

"Inflection point" has a specific meaning in math, and that has led to its use in the business context... Politicians who believe that ordinary people hear "inflection point" as plain English are perhaps betraying an excessive alliance with business and finance.
Silver heard a "call-out" to himself as a highly trained statistics analyst — with a strong background in math and economics. I heard it in an emotional and literary way — with empathy for the less-well educated. I feel sympatico with this Matt Yglesias tweet (from yesterday morning, before Kamala said "inflection point"):

४१ टिप्पण्या:

madAsHell म्हणाले...

Inflection Point - when you put too many meaningless words in a sentence, and begin to sound stupid.

mandrewa म्हणाले...

The irony is that Kamala Harris used the phrase incorrectly. It took me awhile to realize it and I think everyone else missed it also. Once again math is hard. Here's the comment I made on the previous thread, where I realized the problem:

From a comment by Wikitorix:

"Inflection points are where the function changes concavity. Since concave up corresponds to a positive second derivative and concave down corresponds to a negative second derivative, then when the function changes from concave up to concave down (or vise versa) the second derivative must equal zero at that point."

There are a lot of wrong mathematical statements in this thread. This one is the closest to being correct. The first sentence here is true. The second sentence is the usual case, and it's how the concept is taught to Calculus students, but the second derivative does not have to be 0 at an inflection point. Consider the function y=-x^2 for x<0 and y=x^2 otherwise. This function is continuous and differentiable everywhere, but the second derivative is not continuous at 0. Yet 0 still an inflection point.


The problem with your explanation, Wikitorix, is that it only makes sense if you already know calculus. Concavity, derivative, second derivative, function, continuous, and differentiable, these are all concepts that if anything are even harder to understand than inflection point. So even if you are being more accurate in some sense, it still doesn't mean anything to most people.

But reading your comment I dawned on me that I had missed something important. That is Harris is misusing the idea of the inflection point!

What is the common mistake that people make when they are learning about inflection points?

Well they confuse a hilltop or a valley, speaking metaphorically, with an inflection point. And that's exactly what Harris did.

In her mind she's picturing things getting worse and worse under Trump and then when she gets in power things turn around and get better and better. But that's not an inflection point!

A real inflection point would be if for instance things were getting worse under Trump but lately the rate at which things were getting worse had slowed down, but then if Harris comes to power, the rate at which things are getting worse will speed up again. Now that would be a real inflection point.

(And yes, I know that we can come up with functions where Harris's use of the term would make sense, but let's be honest, she's not thinking of any of those unusual functions.)

buwaya म्हणाले...

Most people in college do their best to avoid reading books.
On this matter I am very well informed.

Bob Smith म्हणाले...

Dumbest guy I ever met in the business world had a degree in accounting and an MBA from a top ten school. Got in on a legacy admission because his grandfather endowed a chair. One thing the did teach him? How to hold his coffee cup so everybody in the room could see the university logo.

buwaya म्हणाले...

It is just a verbal trick.
Her speech writer was looking for something less cliched.

An inflection point can look like it is near-linear btw., with whats going on before and since, it is not necessarily a noticable change without perspective.
It is what happens later on the track of the function.

Its not really a valid concept for empirical analysis because it belongs to a process of after the fact curve-fitting, trying to make a theory fit data. Good luck with that.

Rick.T. म्हणाले...

I agree with a comment on the prior thread that it's more likely a tipping point than an inflection point.

john म्हणाले...

Where the second derivative goes to zero.

TML म्हणाले...

"Fork in the road" clearer and more apt. Inflection point implies there's no choice and the direction of the curve is changing. It's like saying, "We're at mile marker 178." It's just a fact, not a choice.

Skeptical Voter म्हणाले...

We bring a new kind of creature to the Swamp. A "Silicon Valley Creature" who speaks of inflection points. Actually I don't think Ms. Harris has the smarts to be a true Silicon Valley Creature but she's smart enough to get their donations.

But the gap between our semi-educated, but highly credentialled, self appointed elites and the deplorable classes is real. Fiftytwo years ago I was fresh out of law school working for a big law firm; I was married and we had a baby on the way which would and did arrive about the time I got news I's passed the California bar exam in December 1968. But I was 24 years old--and the draft took men until their 26th birthday. My 1-A classification came along and I chose not to appeal it. That meant I'd have to perform some sort of military service. Get a JAG commision; see if I could get a Navy officer slot? Enlist in the National Guard? Well a slot in a National Guard company beat notice of the offer of a four year tour as a JAG officer by two weeks. My summer of 1969 was spent at Ft. Polk Louisiana for basic, and for training as a light weapons infantryman. Ft. Polk was starting a new training battalion of 1000 men each week, and upon their graduation 10 weeks later was sending 95% or more of those men straight to Viet Nam. OTOH I was going home to California.

But many of those "kids" ---most of them were at least six years younger than me, spoke a different language. I had visions at the time of a career arguing to juries. If you are going to do that you need to make yourself understood to the jury--and more important understand the jury itself.

It took me a full two weeks to understand that one of the men in my squad had a meaning for the word "hustler" that was different from mine. He was a 19 year Puerto Rican with a girlfriend and at least two kids back in Chicago. He said he was the best parking lot attendant his former boss had ever had because he was a "hustler". That meant he stole from the customers rather than from the boss's cash register. A young draftee from Indiana was angry because being drafted destroyed his career as a White Castle burger stand manager. Another young man's proudest accomplishment in life at the time was being named best high school diesel mechanic in his home county. These are different worlds, and very different vocabularies.

TML म्हणाले...

"Fork in the road" clearer and more apt. Inflection point implies there's no choice and the direction of the curve is changing. It's like saying, "We're at mile marker 178." It's just a fact, not a choice.

Kevin म्हणाले...

Matthew Yglesias doesn't think voters can understand inflection point, but do know enough to change the economic foundation of the country from capitalism to socialism or even communism.

This, people, is your Democratic Party.

mikee म्हणाले...

I believe Trump may have used "bottom line" once or more in his public speeches. But that's a business term, completely unfamiliar to Democrat politicians who never have to worry about such a thing.

alanc709 म्हणाले...

Like most liberal elitists, Matt confuses credentials with intelligence.

Leland म्हणाले...

Told you Silver has envy. Now he thinks a silly two word phrase is a "call-out" (shouldn't that be "shout-out" as "call-out" has a negative connotation?) to him? If there is an inflection point in polling, then it is a negative trend for Biden/Harris, who should be enjoying a post VP announcement/convention bump.

It's really old news days with posts about Nate Silver, Matt Yglesias, Matt Drudge, and Kathy Griffin. Their hay day was over 10 years ago (25 for Matt and Kathy).

Joe Smith म्हणाले...

Average IQ in the U.S. is approximately 100. And they cancel out your vote.

cubanbob म्हणाले...

Kevin said...
Matthew Yglesias doesn't think voters can understand inflection point, but do know enough to change the economic foundation of the country from capitalism to socialism or even communism.

This, people, is your Democratic Party."

That sums it up perfectly. Except that Willie's side piece is using a three dollar word incorrectly.

DKWalser म्हणाले...

When I was in high school, we moved to a rural part of the state. Our next door neighbor was a very nice and talented man who was a meter-reader for the electric company. High school graduate, but not too well read. One day, he and my father were having a conversation over the fence about I don't remember what. I do remember my dad, who was college educated, explaining something to our neighbor and the neighbor looking to me with a blank-what's-he-saying expression. I translated. Our neighbor smiled and replied to my dad. My dad made an additional comment and, again, I translated. The conversation went on for 15 minutes like that.

Dad wasn't putting on a show to impress our neighbor with his large vocabulary (that would have reviled anyone's short of William F. Buckley). That's just how he talked in casual conversation. It's the way he spoke at our dinner table.

madAsHell म्हणाले...

Intersectionalities.....we barely knew thee!!

Mary Beth म्हणाले...

There are people who think that if they don't understand everything someone says, that means the speaker is smart. I am of the opposite opinion. I think it's harder, and takes more intelligence, to communicate simply.

buwaya म्हणाले...

"best high school diesel mechanic in his home county"

That is a greater accomplishment and a better indicator of ability than your usual college BA.

iowan2 म्हणाले...

use new words and phrases (good!) in new ways (good!) but when politicians are giving speeches they should remember most voters haven’t graduated from college. — Matthew Yglesias

What a hoot, Yglesias thinks college attendance increases vocabulary. You don't have to hang around "college educated" very long to disprove this assumption.

Wikitorix म्हणाले...

The problem with your explanation, Wikitorix, is that it only makes sense if you already know calculus. Concavity, derivative, second derivative, function, continuous, and differentiable, these are all concepts that if anything are even harder to understand than inflection point. So even if you are being more accurate in some sense, it still doesn't mean anything to most people.

Yes, but I was responding to someone who used those terms. If you want a layman's explanation, try this one:

Imagine you're driving on a road that has an S bend in it, so you turn left for a while and then turn right for a time. So, your steering wheel starts out turned to the left, and ends up turned to the right. There is some point in between where your steering wheel is at its default, straight-ahead position, even if it's only a brief instant. The point on the road where your steering wheel is pointed straight ahead is the inflection point - it's where you switch from turning left to turning right.

Josephbleau म्हणाले...

Where the FIRST derivative is equal to zero.

Josephbleau म्हणाले...

I missspoke in my post, but won’t wait around to delete it when it shows up so pls ignore.

Michelle Dulak Thomson म्हणाले...

Wikitorix, succinct and clear. I still don't see how it relates to what Harris said, though.

As for Yglesias: Does he really believe that the average student leaves college knowing more than s/he did when s/he went in? There have been studies comparing, e.g., Ivy League freshmen vs. seniors on knowledge of American history, and the freshmen were the more knowledgeable. Yeah, history is all just "names and dates," but we're talking really broad dates, as in "In which half-century was the Civil War fought?" And survey after survey profiling college kids protesting this or that prove that they are utterly clueless about whatever they're protesting. They are happy to make a noise about "climate change," for example, but quite incapable of describing any of the science they are supposedly deferring to.

MayBee म्हणाले...

I have been agreeing with Matt Ygelsias more in the past 2 months than in all the years prior, combined.

rcocean म्हणाले...

I've forgotten what the "inflection point" is and don't really want to remember. In all my stat usage, I never had to care about it, which is probably why i forgot it.

Nichevo म्हणाले...

The question is, did she really want to use the concept of inflection point, or was she looking for cusp, hinge, discontinuity, anfractuosity, turning point?

hstad म्हणाले...

AA - I agree the use of "Inflection Point" is silly because most people are clueless of its meaning or use. But I've been saying for several days now - 'Middle America' which is a center/right country - is at a "breaking point" and disgusted with our 'Elites'. In fact, 'Elites' all over the World are viewed with great suspicion. Look at Brexit and Australia. As I mentioned, Mr. Trump was elected President because he talked to these voters (middle America). More power to him because the Democrats are not talking to these voters. Mr. Trump is not the cause of these things. He's the result of these things. This election could be a landslide for Mr. Trump. Prior to the 'Riots'/'Defund Police' I thought Mr. Trump was a goner due to the 'Pandemic'. But that's slowly behind us and hasn't gained much traction from the voters over the past month, vs. nightly riots. The Democrats gave Mr. Trump and gift by not vilifying rioters and defund the police activists. Average Jane/Joe can't fathom WTH are Democratic leaders doing?

Sally327 म्हणाले...

I wonder how many people would read/hear it as "infection" point. We're kind of sensitive to that right now, and it's not just the pandemic, there's other kinds of sickness stalking the land, racism and hatred and all kinds of bad Trumpian diseases.

The country's got a fever and the only prescription is more democrats in power.

Not Sure म्हणाले...

Looks like "inflection point" is on its way to replacing "epicenter" as the word most frequently misused by people who want to sound educated and reveal that they are not by their verbal overreach.

Sadly, this means that soon the descriptivist dictionaries will recognize "inflection point" as a synonym for "turning point," and the language will get just a little bit less precise. Which suits muddleheaded types just fine.

wildswan म्हणाले...

Strengthen Your vocabulary. How to use Inflection Point and Tipping Pint

Trump got a two to four point bounce from the Democratic Convention. This is an inflectious point to be followed by a tipping pint. At least that's what I learned in college at basketball games and the later it is the more so.

mandrewa म्हणाले...

"Imagine you're driving on a road that has an S bend in it, so you turn left for a while and then turn right for a time. So, your steering wheel starts out turned to the left, and ends up turned to the right. There is some point in between where your steering wheel is at its default, straight-ahead position, even if it's only a brief instant. The point on the road where your steering wheel is pointed straight ahead is the inflection point - it's where you switch from turning left to turning right."

That's actually quite a good metaphor and thinking about it I realized something. It doesn't matter which cartesian coordinate system we choose; the inflection points are going to stay the same.

If we were talking local maxima or minima, then those maxima and minima are going to move around on the function if we rotate the cartesian plane. Or in other words the points where the first derivative is zero change as the reference plane is rotated. But that isn't true for the second derivative, the second derivatives stay constant as we move the reference plane.

I don't know what that signifies. It certainly has nothing to do with Kamala Harris. But it's an interesting property.

Narayanan म्हणाले...

Obama got there earlier

It depends on us, on the choices we make, particularly at certain inflection points in history; particularly when big changes are happening and everything seems up for grabs.
— Barack Obama

Narayanan म्हणाले...

may be i should not be saying this:

kamala says i know willies willie before and after and i know inflexion when i see it

George म्हणाले...

Biden also used "inflection" - looks like it is going to be part of the Democrat's lexicon for the next few months

mandrewa म्हणाले...

"It depends on us, on the choices we make, particularly at certain inflection points in history; particularly when big changes are happening and everything seems up for grabs.
— Barack Obama"


He means "turning point." What are the odds he actually knows what "inflection point" means and in fact intends that? I think that's a zero.

What are the odds this was written by a speechwriter who has forgotten what the phrase actually means? This is probably what happened.

If that's what happened with Harris, then I wonder if it was the same speechwriter. But for some reason, I certainly can't prove it, I suspect Kamala Harris may have written her own speech, or at least the first draft.

Static Ping म्हणाले...

Matt also left out the part that a good chunk of the persons who did go to college only improved their vocabulary thru "woke" jargon.

daskol म्हणाले...

Nate Silver is not a highly trained math or statistical analyst. He's a smart nerd with a gift for self-promotion and a strong interest in baseball and politics, who has shown some creativity and even genius in the application of statistical techniques--mostly running simulations--to generate predictions. But what he does is not particularly sound statistics, even if creative, grab-bagging concepts from classical stats and newfangled probability analyses, and I'm sure he's wrong about the sense in which "inflection point" was used in Kamala's speech. Someone wrote a famous biz book a few decades ago that defined the term more or less as follows, and now the b-school educated folks throw the term around to show they went to b-school. Here's the definition from Investopedia, which should be authoritative here, since it's obviously the sense in which the terms is being used.. And anyway, it's obvious from the context that what the writers actually meant was "tipping point." They just wanted to dress it up a little, which was a mistake indeed, since 10s of millions of people read, or at least bought, Gladwell's book. It was popular.

An inflection point is an event that results in a significant change in the progress of a company, industry, sector, economy, or geopolitical situation and can be considered a turning point after which a dramatic change, with either positive or negative results, is expected to result.

daskol म्हणाले...

I say she obviously meant tipping point because she lists a series of things, on their own having insufficient impact to sway our society, but when you add them up, add up to a major force, a force she's trying to harness or otherwise ride to power, which of course they will use for good.

hstad म्हणाले...

daskol said..."...tipping point...". I agree, but these people (Dems) watch to many movies. I think it came from the movie 'The Day the Earth Stood Still' - Keanu Reeves. When the professor tries to argue with the 'Alien' (Reeves) that only at the "tipping point" does mankind change. Which is somewhat true, but like all pop culture meaningless. Mankind will always repeat past mistakes, especially in this 'cancel culture' environment, because activists want to erase history. Don't teach the next generation about past genocides, they will repeat it.