Author Archive

Sharing insurance costs with the sharing economy

One consequence of the “sharing economy” that hasn’t been widely discussed, at least as far as I’ve seen, is how the externalities are being absorbed. Specifically, insurance costs.

Maybe because it’s an ongoing process, but for both Uber and AirBnB, the companies tell individuals who drive that their primary car insurance should be in use, and they tell individual home- or apartment-dwellers that their renters insurance should apply.

In other words, if something goes wrong, the wishful thinking goes, the private, individual insurance plans should kick in.

When people have tried to verify this, however, they responses have been mixed and mostly negative. The insurance companies obviously don’t want to cover a huge number of people for circumstances they didn’t expect when they offered the coverage.

So, if an Uber driver gets into an accident while ferrying a passenger, it’s not clear whether their primary insurance will cover it. It’s even less clear if the driver is using the Uber app and is on their way to get a passenger. Similarly, if an AirBnB guest falls because of a broken staircase, it’s not clear who is supposed to pay for the damages to the person or the staircase. What if the guest burns down the house?

So far I don’t think it’s been fully decided, but I think one of two things could happen.

In the first scenario, the insurance companies will really refuse to cover such things. To do this they will have to have a squad of investigators who somehow make sure the customer in question was or was not hosting a guest or driving a customer. That would involve suspicion and some amount of harassment, which customers don’t like.

In the second scenario, which I think is more likely given the above, the insurance companies will quietly pay for the damages accrued by Uber and AirBnB usage. They won’t advertise this, and if asked, they will discourage any customer from doing stuff like that, but they also won’t actually refuse to pay the costs, which they will simply transfer to the larger pool of customers. It doesn’t really matter to them at all, in fact, as long as they are not the only insurance company with this problem.

That will mean that the quants who figure out the costs of insurance will see their numbers change over time, depending on how much more the insurance is being called into action. I expect this to happen a lot more for Uber drivers, because if you are an Uber driver 40 hours a week, that means you’re always in your car. So our insurance costs will go up in proportion to how many people become Uber drivers. I expect this to happen somewhat more for AirBnB renters, because the house or apartment is in constant use; if it’s being rented by rowdy partiers, all the more. Our renters insurance will go up in proportion to how many people are AirBnB renters.

That reminds me of a story my dad used to like telling, whereby a friend of his rented out his Cambridge house to a Harvard professor, and when he came back it was totally trashed, including what looked like a bonfire pit in the living room. The professor in question was Timothy Leary.

Anyhoo, my overall conclusion is that the new “sharing economy” businesses really will end up sharing something with the rest of us soon, namely the cost of insurance. We will all be paying more for car insurance and home- or renters-insurance if my guess is accurate. Thanks, guys.

Categories: economics, rant, statistics

Aunt Pythia’s advice

My friends, good morning. Go ahead and let yourself in, there’s hot tea in the pot over there. Somewhat stale cookies as well, somewhere. Come sit on the couch with me when you’ve collected yourself.

Friend, please don’t expect too much from Aunt Pythia this morning, and pretty please: keep it down to a whisper.

Here’s the thing. The TomTown Ramblers, my bluegrass band, had a gig last night. And it wasn’t at some random place, no. It was at Aunt Pythia’s house. And yes, we killed it. It might have helped that we invited a bunch of people who love us and who knew it was their job to tell us how great we were, but still.

Killed. It. It’s dead. Just like the kitchen.

It's always easier to clean up after parties than it seems. Or at least finger crossed about that.

It’s always easier to clean up after parties than it seems. Or at least fingers crossed about that.

Aunt Pythia mentions this because you should all know that, instead of cleaning up the immense amount of empties and stale Doritos, she is stepping carefully over it all to sit on the couch and dole out the advice. But she’s pretty sure she’s off her game, so please add comments to correct her many mistakes below.

Be vigilant, people! Help a sister out in her hour of hangover need! And while you’re at it, please:

ask Aunt Pythia a made-up sex question at the bottom of the page!

By the way, if you don’t know what the hell Aunt Pythia is talking about, go here for past advice columns and here for an explanation of the name Pythia.


Hi Aunt Pythia,

I’m a university student studying science. I find I struggle a lot more than some of my friends in my program, who grasp the concepts faster and more comprehensively than I do. A lot of these people are gifted in the sense that they were segregated during high school for achieving high scores on aptitude tests. I, on the other, scored in the average range on such tests. When I compare myself to my friends, I often feel hopelessly inadequate. It’s like I’m struggling to catch up while everyone around me is moving relentlessly forward. It makes me question whether I should remain in my program and whether I can achieve my ambition of eventually doing research in my field as PhD.

Do you think this is all in my head? Is natural intelligence a significant factor? Do you believe it’s innate or can be built up? Do you think the IQ test (or other aptitude tests for that matter) accurate reflect a person’s talent or “potential”?

Thank you,

Uncertain about Academics


Dear Uncertain,

I don’t know the answer to your questions, but here are a few things I do know which might help.

First of all, you don’t have to be a certified genius to be a scientist. There are plenty of people who become scientists wondering how they got the job, because they’re surrounded by people that “seem like geniuses” and they feel mortal in Comparison. But here’s the thing, they are my favorite people, because they’re doing what they love in spite of feeling out of place. They feel lucky to be there.

Second of all, there’s no reason to think you’re not a genius. People in those partitioned and accelerated programs often get a big jump on college-level classes and sophistication. Moreover, they get a decidedly huge jump on the ability to act as if they already know stuff when they don’t. So if you interpret their casual remarks on face value, they might seem lightyears ahead of you, but who knows. The main point is that a couple of semesters of college is worth an entire high school career, so sit tight and see how things shape up in a few months.

Third of all, and most importantly, do what you love. Yes, there are a bunch of tests to see “how smart you are” and then there are tests in your classes to see “how well you know something,” but all of that should be ignored when you think about who you actually are and what you actually want to do. I’m not saying you’ll never compromise, or that you’ll ignore your professors if they tell you to modify your expectations, but I do want to emphasize that this is your life, and you get to control it, and nobody – and especially no test – has the ability to determine whether you are well-suited to a given topic. That’s up to you to decide.

Finally, my husband thinks that intelligence is something you do, not something you are. I think that it might be more complicated, but it’s a good first approximation. In other words, if you focus on good habits of mind, including being skeptical, disciplined, curious, and earnest (with a good dose of humility), then you will be far more prepared for a lifetime of science than by being anxious, competitive, or even cocky.

I hope that’s helpful!

Aunt Pythia


Dear Aunt Pythia,

I think you blew it in your answer to “too sad for acronym” in this Aunt Pythia post from a few weeks ago. I’ve been monogamous for going on 45 years, so you can take my opinion for what it’s worth BUT:

The key point is mathematicians are people, too. It’s fine to talk math with a lovely stranger, but at some point you have to say “Hmm, that’s all interesting. How did you come to be interested in that problem? Where did you do your undergraduate work?” and then, “Oh, that’s interesting, where are you from originally?” followed by “Ah, yes, I’ve been there. Have you been to Chez XYZ? Yes, that’s a great restaurant.” After a while, you’ll get to, “Do you have a family? What do they do for a living? Ah, very interesting. Mine are pretty colorful, too…” And pretty soon you aren’t talking math any more, and you can say “do you want to go grab a drink/coffee/dessert?”

And after that it’s up to you. But you need to stop feeling sorry for yourself; otherwise none of this will work.

Good Scientist Trying to be a Good Human

Good Scientist,

It’s great advice, to be sure. However, I think you’re missing half the context if you start with the conversation already happening. Mostly what I was trying to counter with “too sad for acronym” was the idea that you could initiate a conversation with someone on the assumption that you’re interested in (their) math, and then use the opportunity to hit on her.

In other words, if you just happen to be having dinner with someone, your advice above is great. But if you got her to have dinner with you by saying, “I’d love to discuss your paper!” then not so great. In fact it will seem to the person like a bait and switch.

Basically all I was hoping to achieve with my advice was a way to avoid that, by deliberately creating a bunch of opportunities where you would eventually “happen” to have dinner with someone. After which you could follow the advice above.

Aunt Pythia


Aunt Pythia,

I am a first year PhD student in math and just got awarded an NSF graduate research fellowship. Prior to receiving this fellowship, my department guaranteed 25k for three years, part of which is a small summer stipend (about $6000). When I told my department I got an NSF, I asked if I could combine the summer stipend with NSF and they said that I would not be able to do this and that they were rewriting/changing my funding letter that they gave to me last year.

I was bummed out when I heard about that, but not too upset. But then I heard (aka not 100% sure) that an incoming grad student next year got an NSF but he wanted to teach (which you can’t do while taking NSF money), so the department said they would give him $7000 extra his first year (so 32k total) so he can defer his fellowship and teach. Also, because the department doesn’t care or it’s just something they have overlooked, I think (again not 100% sure) if you get a job over the summer, you can still get the summer stipend, which doesn’t seem fair to me since they won’t give it to someone who has a fellowship and staying at school yet they’ll give it to someone who is working for someone else.

I know money isn’t everything and it’s a small amount of money and I should just be grateful for having the NSF in the first place, but I just feel jipped especially since I am now saving the department/school a significant amount of money for the next 3 years (NSF pays a 34k stipend + 12k tuition for 3 years)!

How much room do students have to push/negotiate with departments? I know some schools give out bonuses for bringing in outside money. Clearly, mine is not one of those schools. I *definitely* do not want to get on someone’s bad side or look that money hungry. Am I being way too whiny and should I just suck it up? Or should I say something? I don’t want to throw anyone under the bus, so how would I even go about doing this (especially since I am *so* timid and shy)?


Dear TTFL,

Gosh, I have no idea. I mean, beyond offering to teach, so your situation would be more analogous. I mean, as of now, unless my head is still drunk, you don’t actually have a conflicting story.

But I don’t know what the standard practice is, and the only person in this household who does is currently snoring. That means it’s an awesome question for a hangover column, because I’m betting some of my readers will have opinions about this.

In any case, it is indeed fantastic that you got that NSF! Congratulations!

Aunt Pythia


Good Day,

My name is (something), am here to testify of a great spell caster called Dr. X. This man is truly a great spell caster indeed. I contacted this great man for a help and just within two days my problem was completely solved. My ex- came back to me just within 48 hours begging me to accept him back. Now we are fully back again as lovers, all thanks to Dr. X and his great temple for restoring pace to my life. His contact email address is,

He is also specialized in the following.

1. He can help you cast a spell to get pregnant.
2. He can help you cast a Death Spell.
3. He can help you cast a Promotion spell.
4. He can help you cast Lottery spell.
5. Spell of luck.
6. Spell of Finance.
7. If you have been scam before, he can help you cast a spell to get your money back.
8.He can help you solve your low sperm count.

And many more.. contact him on his private email and explain what you want him to do for you i assure you he shall help,His email is:

Good Luck


Dear (something),

HAHAHAHA I’ll take #7.


Aunt Pythia


Dear Aunt Pythia,

Not too long ago I graduated from a good school, landed a great job, and came out as gay and somewhat naively thought that with all of this things would “get better”.

I’ve never really been on a date before and still feel like I’m making up for awkward middle/high school development most folks around my age have gone through (super shy around guys, does he “like me like me”…etc.).

One thing that I didn’t account for and never really thought would be an issue is race. I happen to also be black, and find that there seem to be a looooot of people who either feel that they simply don’t find black guys attractive, creepily fetishize it (lots of chocolate references and expectations that I’m super aggressive), or don’t even consider a date possible because they don’t tend to think it’s possible for black people to share their interests.

It doesn’t seem unique to white people either. I noticed this before when people thought I was straight but it seems really prominent/visible on the gay side of things and the data available suggests this (see this for example).

I respect people’s preferences and totally understand I’m not the center of the universe…but what am I supposed to do now? It almost doesn’t really feel as though coming out was worth it anymore (and frankly all this hurts more than I thought) especially if I’m just hoping to find mutual attraction for minorities within a minority group. What’s worse is I’m wondering if things only “get better” for certain people. Any tips, or words of wisdom are welcome. Until then I’ll just keep telling people that I too “love to laugh”, listen to NPR, and judge Kardashians.

Just Like You

Dear JLY,

First of all, congratulations on all your accomplishments! Sounds like you are awesome and crush-worthy.

If it helps, I have cute white friends who leave what I think of as large American progressive cities because they are gay and the scene is too small. So you’re not alone in finding this difficult.

If you needed more evidence, I just googled “good scene for black gay men” and I came up with an article entitled, Are All Single Black Gay Men Bitter?

Here’s the thing, I know nothing about being a black gay man. But I do know statistics, and I suggest you play the numbers. That would mean spending time in New York or San Francisco whenever you can to meet people in a larger dating pool. I have no idea where you live normally, but make it a point to visit whenever you can, on vacations or even weekend trips. Keep meeting people, and get used to hanging out in a social and fun way, and eventually work your way into a date.

I wouldn’t suggest telling anyone that you’ve never been on a date before: fake it til you make it on that score. And anyway, that’s not important, because being on a date is just like hanging out and talking with someone. The only real difference is, if it goes well, you can get all crushed out on them and not feel weird about it.

Good luck!

Aunt Pythia


Congratulations, you’ve wasted yet another Saturday morning with Aunt Pythia! I hope you’re satisfied, you could have lazed about in your pajamas for longer. Oh wait, you’re still in your pajamas, I take it all back. Well done.

But as long as you’re already here, please ask me a question. And don’t forget to make an amazing sign-off, they make me very very happy.

Click here for a form or just do it now:

Categories: Aunt Pythia

Nick Kristof is not Smarter than an 8th Grader

This is a post by Eugene Stern, originally posted on his blog

About a week ago, Nick Kristof published this op-ed in the New York Times. Entitled Are You Smarter than an 8th Grader, the piece discusses American kids’ underperformance in math compared with students from other countries, as measured by standardized test results. Kristof goes over several questions from the 2011 TIMSS (Trends in International Mathematics and Science Study) test administered to 8th graders, and highlights how American students did worse than students from Iran, Indonesia, Ghana, Palestine, Turkey, and Armenia, as well as traditional high performers like Singapore. “We all know Johnny can’t read,” says Kristof, in that finger-wagging way perfected by the current cohort of New York Times op-ed columnists; “it appears that Johnny is even worse at counting.”

The trouble with this narrative is that it’s utterly, demonstrably false.

My friend Jordan Ellenberg pointed me to this blog post, which highlights the problem. In spite of Kristof’s alarmism, it turns out that American eighth graders actually did quite well on the 2011 TIMSS. You can see the complete results here. Out of 42 countries tested, the US placed 9th. If you look at the scores by country, you’ll see a large gap between the top 5 (Korea, Singapore, Taiwan, Hong Kong, and Japan) and everyone else. After that gap comes Russia, in 6th place, then another gap, then a group of 9 closely bunched countries: Israel, Finland, the US, England, Hungary, Australia, Slovenia, Lithuania, and Italy. Those made up, more or less, the top third of all the countries that took the test. Our performance isn’t mind-blowing, but it’s not terrible either. So what the hell is Kristof talking about?

You’ll find the answer here, in a list of 88 publicly released questions from the test (not all questions were published, but this appears to be a representative sample). For each question, a performance breakdown by country is given. When I went through the questions, I found that the US placed in the top third (top 14 out of 42 countries) on 45 of them, the middle third on 39, and the bottom third on 4. This seems typical of the kind of variance usually seen on standardized tests. US kids did particularly well on statistics, data interpretation, and estimation, which have all gotten more emphasis in the math curriculum lately. For example, 80% of US eighth graders answered this question correctly:

Which of these is the best estimate of (7.21 × 3.86) / 10.09?

(A) (7 × 3) / 10   (B) (7 × 4) / 10   (C) (7 × 3) / 11   (D) (7 × 4) / 11

More American kids knew that the correct answer was (B) than Russians, Finns, Japanese, English, or Israelis. Nice job, kids! And let’s give your teachers some credit too!

But Kristof isn’t willing to do either. He has a narrative of American underperformance in mind, and if the overall test results don’t fit his story, he’ll just go and find some results that do! Thus, the examples in his column. Kristof literally went and picked the two questions out of 88 on which the US did the worst, and highlighted those in the column. (He gives a third example too, a question in which the US was in the middle of the pack, but the pack did poorly, so the US’s absolute score looks bad.) And, presto! — instead of a story about kids learning stuff and doing decently on a test, we have yet another hysterical screed about Americans “struggling to compete with citizens of other countries.”

Kristof gives no suggestions for what we can actually do better, by the way. But he does offer this helpful advice:

Numeracy isn’t a sign of geekiness, but a basic requirement for intelligent discussions of public policy. Without it, politicians routinely get away with using statistics, as Mark Twain supposedly observed, the way a drunk uses a lamppost: for support rather than illumination.

So do op-ed columnists, apparently.

The New York Real Estate Mafia

Sometimes your conspiracy theory turns out to be absolutely true.

Over the past few years, primarily due to conversations I’ve had at my weekly Alt Banking meetings, I’ve become increasingly concerned about the crazy real estate industry in New York City and New York State. A few pertinent facts:

I am really hoping we can clear up this mess and end the corruption in the New York real estate market soon. Housing is a big deal.

Categories: Uncategorized

Occupy Summer School #OWS

I’m super excited to announce that the Alt Banking group is creating a summer school program, which we’re calling Occupy Summer School. The project has a webpage with more details, but briefly:

  • It will last three weeks, taking place in a downtown Brooklyn high school.
  • The first week we will bring in cool and inspiring organizers and activists who will hopefully connect with the kids
  • The second week we will delve into topics and the kids will decide what they care about and, by the end of the week, what they will protest and how,
  • The third week the students will plan the protest, including training on safe protesting techniques, they will stage it and write it up, and hopefully help the issue get media attention.
  • So far we have ideas for the first week, including a few of our really interesting and thoughtful members going to facilitate conversations around what’s going on in Baltimore, and how to stage a creative protest, involving our very own Marni Halasa:marni
  • We are starting to line up speakers for the second week, but we are waiting on a focus group to come back to us from the students to see what topics they get really excited about. We want them to more or less lead the way.

What an exciting project! I can’t wait for it to start.

Categories: #OWS

China announces it is scoring its citizens using big data

Please go read the article in the Dutch newspaper de Volkskrant entitled China rates its own citizens – including online behavior (hat tip Ernie Davis).

In the article, it describes China’s plan to use big data techniques to score all of its citizens – with the help of China internet giants Alibaba, Baidu, and Tencent – in a kind of expanded credit score that includes behavior and reputation. So what you buy, who you’re friends with, and whether you seem sufficiently “socialist” are factors that affect your overall score.

Here’s a quote from a person working on the model, from Chinese Academy of Social Science, that is incredibly creepy:

When people’s behavior isn’t bound by their morality, a system must be used to restrict their actions

And here’s another quote from Rogier Creemers, an academic at Oxford who specializes in China:

Government and big internet companies in China can exploit ‘Big Data’ together in a way that is unimaginable in the West

I guess I’m wondering whether that’s really true. Given my research over the past couple of years, I see this kind of “social credit scoring” being widely implemented here in the United States.

Aunt Pythia’s advice

People! PEOPLE! Aunt Pythia needs your help!!

Here’s the thing, dear readers. Aunt Pythia screwed up royally. She told you a couple of weeks back that she had plenty of questions, and in a sense she did, but that was misleading, and moreover it has backfired tremendously.

You see, Aunt Pythia finally read all those questions, and for some reason they were almost entirely spammy, nonsense questions, and moreover none of them were at all about sex, so that’s also a terrible fact. Don’t do this to me, it’s uncalled for.

But the worst part is that, since Aunt Pythia (wrongly) declared her mailbox full, she’s not receiving new letters! In fact, it’s a dire situation, and Aunt Pythia might be shutting down the advice bus and selling it off for spare parts before the week’s end unless something is done.

Is this not the saddest sight in the whole wide world? And it's made even sadder because it's in black and white.

Is this not the saddest sight in the whole wide world? And it’s made even sadder because it’s in black and white.

We’re talking urgent sex questions, down below, stick ’em in, and pronto. Aunt Pythia desperately loves her job and doesn’t want to stop. Her standards are low but please make it coherent and sex-related.

That request once again:

ask Aunt Pythia a made-up sex question at the bottom of the page!

By the way, if you don’t know what the hell Aunt Pythia is talking about, go here for past advice columns and here for an explanation of the name Pythia.


Dear Aunt Pythia,

Super Pi day = “Once in a century”?

What about in Europe where dates are written:

So April 31, 2015 is:

Dated in Europe

Dear DiE,

First, condolences for your unfortunate sign-off.

Second: hey, I was thinking the same thing – what if you write it in some other base? Like, using this online calculator, you can convert any base 10 number into whatever (integral) base you’d like. They even have the option to use “pi” or “e” or “sqrt,” because they are good nerds! That gives you a ton more “Super Pi Days,” if you’re creative enough.

And if you do it more generally, you could even choose a non-integral base! Hey, it wouldn’t surprise me to learn that, allowing the base to be arbitrary, and allowing dates to be written European or American style would mean that most dates qualify as “Super Pi Days.”

To be clear, it doesn’t mean those days becomes less super, just that almost every day is super. Or maybe pi is always super. In any case, it would be an awesome excuse to party every day whilst feasting on pie.


Aunt Pythia


Dear Aunt Pythia,

When I grade, I spend about 10 minutes grading. Then I spend 5 minutes thinking the world is doomed. Then I calm down a bit, and spend 5 more minutes thinking that just my students are doomed. Then I spend 5 minutes thinking about how it’s all my fault because I’m an incompetent teacher. Then I spend 5 minutes thinking about how little anything I could have done differently would have made a difference. Then I spend 5 minutes thinking about how I’m wasting my time with these idle thoughts, and 5 more minutes considering that not having these idle thoughts would be intellectually dishonest. Around this time, I’m ready to go back to grading, at which point the cycle repeats itself.

Obviously, I can’t really afford to always spend 4 hours doing grading that should really take 1 hour.

Any advice for dealing with this?

Feeling Absolutely Incompetent Looking Upon Results on Exams


Here’s the thing. Your expectations are all wrong. Instead of being disappointed when not everyone understands everything, you have to be overjoyed when someone understands something. Also, you need to learn how to trick yourself into a success story. Let me tell you how it’s done.

What I do when I grade is create an internal environment inside my head, kind of a suspension of disbelief zone, where I lower my expectations to to the point where I’m like, man I hope someone passed this test.

Then I charge ahead with grading like a steamroller, practically holding my breath the entire time, and I don’t let myself breath until all the grades are added up and plotted in a histogram. At that point I’m like, ok here’s the distribution of scores, I will define the grades so that, by construction, a good portion of people have passed. That way my fantasies always come true, even if the scores are crowded down around 17.

Good luck!

Aunt Pythia


Dear Aunt Pythia,

What is your take on what is happening in Seattle with restaurants? To me, it was predictable that restaurants would not be financially viable with $15 an hour wait staff. We apparently assumed that it would work and so forced the issue on that basis. Was this another case where our left-wing activist buddies ignored science and economics, or am I just too much in the hip pocket of rapacious big business?

Between Planets

Dear Between,

Wait are you talking about recent closures of Seattle restaurants blamed on the minimum wage hike? Well, I google “Seattle restaurants minimum wage” and immediately came upon this article arguing that it is a bogus claim.

In any case restaurants go out of business all the time, it’s a crazy industry. Anybody looking for evidence that they are going out of business for a given reason would have plenty of statistical noise ready and willing to distract them. I’d have to look at many years of data to be convinced.

Aunt Pythia


Dear Aunt Pythia,

I try not to pay attention to politics, but I have become increasingly worried as I can’t help but hear about things that seem threatening. I want to live in the same country that I grew up in, where we were free to think what we wanted, and if we dared, to speak about it. I also liked the fact that we voted for representatives who served in Washington, making votes for us. I don’t want to live in a new Venezuela with a new supreme leader. I hope that I am panicking needlessly. Sorry for a political topic. I am generally an insurgent, in that my first vote for president was for Eldridge Cleaver. In 1980, I voted for John Anderson. I am sorry that I voted for Ron Paul in 1988, but that is water over the dam. I would like to vote for Elizabeth Warren, if she would dare to run. What can we do?

Sonoma Soul


Good news, Bernie Sanders is running. Bad news, money in politics paired with the new micro-targeting strategies probably mean that no insurgent will ever win again. This is ironic considering that Obama was an insurgent and won but also built the modern micro-targeting machine. He closed the door behind him.

Aunt Pythia


Congratulations, you’ve wasted yet another Saturday morning with Aunt Pythia! I hope you’re satisfied, you could have lazed about in your pajamas for longer. Oh wait, you’re still in your pajamas, I take it all back. Well done.

But as long as you’re already here, please ask me a question. And don’t forget to make an amazing sign-off, they make me very very happy.

Click here for a form or just do it now:

Categories: Uncategorized

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