Tuesday, November 3, 2015

Congolese space entrepreneur

Another independently wealthy space nerd trying to launch things! In the DRC!

“I will do my utmost to bring that rat back alive,” he says. “But if not, there’s a lot of rats in Kinshasa.”

Tuesday, October 20, 2015

Science is hard

This is a great story of how the cure for scurvy was forgotten. Basically, the British realized early on that lemon juice would prevent it very effectively, but they didn't really know why (and perhaps more importantly, they seem to have been fairly unaware of this ignorance). So when they switched to other solutions that various theories held would be equally effective (eating preserved limes with the vitamin C destroyed, avoiding tainted meat but failing to eat fresh meat, etc), the scurvy came back. It wasn't until the mid 20th century that the true explanation was finally verified. Turns out, science is hard: it's really easy to come up with explanations for facts and really hard to be sure which one, if any (of the ones yet thought of), is right.

Serendipitously, even though that story was published a few years ago, I read it the same day this perfectly appropriate xkcd cartoon was published:

I like to make fun of engineers and physical scientists for how easy they have it* since rocks kinda just obey a few laws and are easily controlled and predictable. Experiments are easy to control and replicate and there aren't the plethora of confounding factors that come with humans being human and exercising their infinitely faceted free will. I do think this makes economists very good at thinking about alternative explanations and being very harsh judges of any inference from data; the success of this approach is why economics is invading the other social sciences and even medicine. On the other hand, introspection is useful guide when trying to think of new hypotheses about human behavior that the physical scientists don't have at their disposal, and the obvious difficulty that created for scurvy makes me(even more) amazed at how far science came in such a short time. Good job guys.

*Yes I'm kidding.

[Link stolen from SlateStarCodex]

Thursday, October 15, 2015

re-SMBC part 6

More accurate redo of SMBC number 3823:

This is a bit inaccurate, because of course an economist wouldn't even ask why...

Sunday, October 11, 2015

Thanks UT Austin!

Daniel Hamermesh, one of my very favorite economics bloggers, is heading to Australia, at least in part due to concerns over campus carry legislation at his current institution in Texas. Thanks Texas!

I wonder whether his UT colleague Max Stinchcombe, who visited UQ most of last year, told him how nice Australia is. Word of mouth may also being playing a role at Berkeley: four Berkeley Econ graduates in three years (and counting, I hope) have crossed the pond.

(I mean, frankly I'm surprised it's not higher; doesn't Australia seem like a better option than being forced out of California after 6 years of learning to appreciate a good climate and the great outdoors?)

Also: I really love to see voting-with-your-feet in action.

Thursday, October 1, 2015


I was traveling for most of August and September but now that I'm back in my office, I've gotten caught up on most of the blogs I follow. A few weeks back Alex Tabarrok had a cute mathy post on the Frechet probability bounds with the warning "super wonky!" in the title. My reaction was first "duh" and then "wait, this actually has a name?" (This probably goes a long way to explaining my teaching evaluations :)

I love Alex's explanation and love that he posted it; I in no way mean that it's too trivial to be interesting. But it's such a perfect example of something that looks scary if you write it down in formal notation and give it a high-falutin name, and it scares people off who don't read math all the time so that you have to put "super wonky!" warnings on things, but if you think about a simple example for a few seconds it's incredibly simple. Much simpler than the concepts involved in most of Alex's non-wonky posts.

Anytime I teach anything involving math (and I try not to teach anything that doesn't involve math, math is too fun!) I spend a significant amount of time trying to convince students that math is not actually scary and that they definitely shouldn't memorize equations for everything. If you understand that a linear relationship is just something that starts at a particular spot and then follows a particular slope, you don't need to memorize the equation for a line, or the point-point formula, or the point-slope formula, and I loathe that the ubiquitous approach presents those three separate equations that students then copy down and memorize.

Here's an example of the Frechet probability bounds. If 80% of people are Caucasian and 70% are Christian, there has to be some overlap. In fact, at least 50% of people have to be both Caucasian and Christian. On the other hand, there might be more overlap; it could be that 70% of people are Caucasian Christians, 10% are other Caucasians, and the other 20% are Buddhist Asians. Take a second to picture the possibilities and those numbers will be obvious to you; if you get stuck, see Alex's post for a nice way to diagram it.

That's it. One tiny concept (your groups of people have to overlap somehow to fit within the population you have) with some fancy notation and a fancy name that scares people off.

I should add, I'm not actually opposed to fancy names, in fact I love jargon of all kinds when used to improve precision and economy of language rather than to obfuscate or sound smart. When I went to mathcamp in high school and learned the name for the "pigeonhole principle" I also thought it was hilarious that this warranted a name - all it says is that if you have more pigeons than holes, some pigeons are gonna have to share holes (in fact this is the fundamental concept at work in the Frechet bounds as well) . But it's actually great that it has this name because it can be applied in creative ways in much more complicated proofs that don't immediately seem to have anything to do with counting holes, and all you have to do is say "by the pigeonhole principle" for the experienced reader to quickly deduce what are the pigeons and what are the holes and how their relative number is relevant, without you having to spell it out.

Tuesday, September 29, 2015

research advice



[Link stolen from Chris Blattman, iirc.]

Tuesday, September 15, 2015

Oz makes it to the NFL



Highlights include:

  • Oh, no break between quarters? There is that. 


Wednesday, September 9, 2015

hot pink revenue management





Tuesday, July 21, 2015

thinking on the margin

They say economic thinking is thinking on the margin, and that's very true, in fact so true our brains sometimes ignore everything else except the current margin. As I've recently discovered, I don't even know what my preferences are away from the margins I have experience with.

I try to be "mostly vegetarian" which in the U.S. led me to basically never cook meat except for a $9 loss-leader thanksgiving turkey once a year. I really love vegetables and fried tofu and lentils and TVP anyway so I thought the high price of meat was basically irrelevant to those habits, at best a handy way to keep delicious overpriced steak out of mind.

Then I moved to Australia where fresh produce costs about three times what it does in California (where it is unusually cheap and varied and wonderful), and even though meat costs more as well, the relative price has plummeted. Without thinking about it, and without abandoning my conscious aversion to buying meat in the first place, lo and behold I find myself grilling chicken every couple of months. And putting $3.50/kg chicken in my curries instead of $7/kg tofu.

My preferences didn't change, my expected consumption habits didn't change, but then in that moment at Costco when I can't turn down the $6 rotisserie chicken right after leaving the Asian grocery store with only one package of tofu in the hopes that I'd run into a better sale soon, somehow my actual consumption habits did change. That's the invisible hand in action, not caring that I'm not aware of the margin and forcing me towards the new one anyway.

(Overall it seems that the prices don't stop Australians from kicking butt in this department overall. Even compared to California.)

Monday, July 20, 2015


(Link stolen from MR.)

Friday, July 17, 2015

ignore Hanlon's More Optimistic Razor at your own peril

(Absolutely no good can come from throwing gasoline onto fires started by arsonists, but sometimes emotions override logic and you just want to watch some stuff burn...)

The problem with social justice warriors is the negligence of Hanlon's razor. Don't attribute to malice that which can be explained by ignorance.

Actually, Hanlon's razor isn't quite right. The problem with social justice warriors is that they frequently attribute to malice what can be explained by misguided good intentions, or non-misguided good intentions, or good but different intentions, or ignorance. Let's call it Hanlon's More Optimistic Razor.

This is highly counterproductive. My advice to them, which I truly hope they take since I usually share their goals, is to replace their vinegar with honey, and to do so not to strategically lure flies but because HMOR makes you honestly want to.

I'm not a particularly empathetic person myself, so I am constantly surprised at the extent to which people think their views are the only possible views with good intentions. Democrats think Republicans can only want tax cuts to reduce their personal tax bills or because they hate poor people. Republicans think Democrats can only want tax hikes because they are lazy or because they hate rich people. Christians think atheists can only be motivated by selfish immorality and atheists think evangelists can only be motivated by bigotry and hatred. The most rudimentary empirics you can imagine completely discredit all of these views, of course, but they persist.

These examples might be blatant enough that, when pushed, people will usually back off and admit that others' motives aren't quite as bad as they make them out to be. But the gut feeling and rhetoric persists. And there are plenty of other less salient examples where the acknowledgement of equally well-intentioned, but different, goals, definitely doesn't match reality. I study social norms, in particular differences in beliefs between individuals, and I cannot count how many times I've had examples responded to with "but... that's not really the same thing as different norms, because only one of them is a real belief, the other one is just concocted to justify preferences." No one can really think you should eat meat, or that you should allow guns to be legal, or that you shouldn't go to college, or that should beat women who reveal too much skin in public. But even in the most extreme examples, I firmly believe, not without evidence[1], that most people are inherently well-intentioned and simply have different goals and/or beliefs about how those goals can be attained. In fact, limiting ourselves to American/first world politics for the moment, I'd go even further and say it's really just the latter. People are mostly well-intentioned, and people mostly want the same things for the world, they just disagree about how to best achieve it.[2]

So why did I start this ramble by pointing fingers specifically at social justice warriors? Well, that's the fire I was referring to. Unlike other political battles, the war between the SJWs and the Scott Alexanders of the world seems to me to be almost exclusively fueled by the neglect of HMOR on the former side and the understandable defensiveness that the latter side responds with. If we could all just stop treating people we basically agree with who do things a little differently as evil, the entire war would end.

The specific motivating issue that leads me to write about this right now[3] is this whole pointless fight over the confederate flag that we're going through yet again. I am so bored by the confederate flag. And by politically correct vocabulary. And by correct pronouns and titles. And by innocuously-mistaken-yet-Bayesianly-reasonable-and-appropriately-corrected assumptions. There's a fair chance I'll be attacked or lectured for that paragraph, but I'm frankly too bored with the topic to respond, so apologies in advance.

The problem, for SJWs, with not being bored with the confederate flag is that it is counterproductive. Trying to make people feel bad for doing something they believe in will only make them more adamant about doing it. I have a model of social pressure that explains why. It's a double-whammy: If you attack me for flying the flag, then by keeping it up I get to signal that I am a person who does what I believe in even in the face of adversity. That's a pretty great reputation to have. And, you're making my friends pay more attention to the issue, leading them to pour even more approval on me. This is why I'm not remotely surprised that support for the confederate flag is increasing among Republicans as it falls overall.[4]

Obviously I'm against racism and a lot people who fly the confederate flag do so in part to express racism. But the act of flying the flag itself isn't harmful, so for the sake of the majority of the flyers who are well-intentioned and just want to express some southern pride[5] or have a nostalgic attachment to it or who want to make some statement about states rights, I just don't care. Even for the sake of the well-intentioned racists who have a different enough life experience that they honestly feel moral justification for their views... I'll vehemently try to convince them that they're wrong but it's a hell of a lot more effective to appeal to the inherently good person inside than to tell them that their views are so black-and-white plain-and-simple evil they shouldn't even be expressed.[6] In the meantime, that's all it is, an expression.

So please, for your sake, can't we all just get along?


[1] In fact, I was shocked that this apparently qualifies as a new surprising theory. Isn't it obvious!?

[2] And that's why people should put more bayesian weight on the opinions of economists, since this is what we spend our whole lives studying after all :)

[3] Other than my current sleep deprivation which makes me rambly instead of motivating me to focus harder on the work that has the imminent deadline that is the source of the sleep deprivation in the first place..

[4] I'm actually annoyed that I didn't blog this before seeing that link because I was going to predict exactly that. Oh well; I know I was right :)

[5] And by the way, the need that southerners feel to express their southernness, I can tell you for absolutely certain from my own experience, is strongly amplified by the constant dismissive derision from the rest of the country. Yet another perfect example of perilous neglect of HMOR...

[6] Yes I know that the debate isn't over the right of individuals to fly it, but the psychological impact of a debate over whether a state's citizens are allowed to choose to fly it on a government building is hardly any different.

Tuesday, July 14, 2015


Remember 10 years ago when we were so excited that a new mission to the edge of the solar system was being launched, to map the one former planet that hadn't yet been seen up close, but then, well, it was 10 years away, so we kinda forgot about it?

It's here! And holy crap:

Sunday, June 28, 2015

universal basic income

Yay, Utrecht is going to experiment with a universal basic income scheme. That is, a stipend regardless of other income. And they seem to be doing it in collaboration with economists, although the article is extremely thin on details.

Unfortunately, the coverage omits the number one reason to try such a scheme: it's a social safety net that doesn't result in exorbitant implicit marginal tax rates! That is, it doesn't discourage you from working due to the fear of losing your benefits. This is a very real, very big problem with social safety nets as currently ubiquitously implemented. Even >100% marginal tax rates occur, and it doesn't have to get nearly that high to have a big impact on work choices.

Friday, June 26, 2015

marriage equality!

Boy I wish I were in San Francisco for this Pride weekend!!

And now that we have marriage equality, we can move on to debating whether government should be involved in marriage at all :) (I still think this.)

Wednesday, June 17, 2015


As I mentioned in my last post, I have a gut affinity towards utilitarianism, but am confused about the details and not at all up to speed on philosophy in general. Part of my confusion comes from witnessing, and not being sure what to make of, the divide between moral libertarians and utilitarian libertarians. The former group is the one that believes in the inherent value of liberty regardless of the consequences, and the latter group believes in liberty because of the consequences.

The strange thing is that there is a great deal of opposition to utilitarianism among the moral libertarians (for example, Saint-Paul). It seems to me that the root of the opposition is a desire to discredit the philosophy so tightly linked to the argument for redistribution of wealth.[1] I suspect at least a few of the logical arguments against it are designed ex post to support that goal, which doesn't make them wrong, but justifies additional suspicion.

Basically, over time I've concluded that my heart is a moral libertarian and my brain is a utilitarian libertarian[2], and boy isn't it lucky that the conclusions coincide so well. But the more I think about it the less conflict I think there is and the more I just think utilitarianism is not very useful except at the broad gut-level analysis I employ it as.[3]

So back up - where does my affinity towards both utilitarianism and liberty come from?

Utilitarianism: I know this is something I care about because a) it's just obvious to want to maximize well-being, and b) in my daily life, I hate inefficiencies and frequently incur personal costs to get rid of them. I'm pretty sure my boyfriend is the only one who has ever accused me of being a generous person, but when he does it's always for things like driving out of my way to drop people off rather than letting them all pay extra money to spend hours on buses, or for organizing collective actions when I'm pretty sure a valuable public good won't be provided if I don't personally step up to the plate. My best friend can also confirm my inclination to meddle when I see people doing things inefficiently...

Libertarianism: I do not like being told what to do. That's pretty much the sum of it. Obviously that was only the initial root of it, and as a kid I formulated a value for liberty in tandem with a value for personal responsibility, and in college as an economics student I added onto that a belief system about the economy and larger-scale political issues. But fundamentally, I'll admit it, it comes down to a really, really strong desire to live and let live.

If I were unique in this desire and if markets didn't work they way they do, that would be a tough spot to be in. I personally value liberty for its utility to me, and if the rest of the world was happier being tightly regulated, I would have to just make peace with that[4]. But I don't think there's a conflict. No one likes being told what to do, even if they don't care as strongly as I do. Liberty inherently provides an enormous deal of utility! And luckily, liberty also allows for decisions that aggregate into much, much richer societies. Seems like a pretty utilitarian perspective to me.[5]

So what's the problem with utilitarianism? If I can use utilitarianism to support by libertarian view with as much conviction as someone can use it to support their enormous-welfare-state preferences, that's a bad sign. The argument becomes a (mostly, see [3] again) empirical question (which is where the field of economics comes in). But that's also kind of a good thing - if we can admit that we have common ground in wishing the world well, we can move on from the philosophy to the empirics.

I don't think that the practical difficulty of interpersonal utility comparisons and the prediction of the utility implications of various policies is a challenge to the principle of utilitarianism. If it's pretty obvious that I make my friends better off by organizing a carpool, it can be equally obvious that mutually-agreeable trades makes people better off. Difficulty in distinguishing shades of gray doesn't mean that the ends of the spectrum aren't black and white, or that we shouldn't try.

I started this saying I'm confused and uninformed on the whole topic, which is true but diminishingly so, so please tell me where I'm wrong :)

With spectacular timing, while I've been writing this in my head the last few days until I had a chance to actually type it, Tyler CowenScott Sumner and Bryan Caplan have relevant posts with which I mostly agree. I think. (There may be others in the thread that I've forgotten; apologies. And one of those is from 2010 but I just read it, I'm not sure how.)


[1] I believe that was the original motivation Bentham had for defining it, right? Or is that another biased simplification by moral libertarians that I shouldn't have taken at face value?

[2] Frequently also referred to as a bleeding heart libertarian, but I don't much like that phrase.

[3] I also know barely anything about Austrian economics but I think this is also one of their main points, that interpersonal utility comparisons are impossible and therefore mainstream economics is invalid etc. I definitely don't go that far. Interpersonal utility comparisons are in principle impossible but a rough approximation is feasible, credible, ubiquitous, inevitable, and useful. See Tyler's link above.

[4] Similarly, I'm against public finding for radio and tv and arts despite the fact I personally greatly benefit from those subsidies. My unusual preferences don't give me the right to be subsidized.

[5] There are systematic differences you see between utilitarian and moral libertarians resulting from this acceptance of utilitarianism; accordingly, I'm perfectly fine with a minimal social safety net and policies that improve clearly failing markets.

Thursday, June 11, 2015











Monday, June 1, 2015

happy winter

Apparently it's the first day of winter here in Australia. An accident of history: the military used to switch uniforms with the changing seasons at the start of the month, and therefore June 1 (ahead of solstice on the 21st) became known as the official start of winter.

This is a case of two wrongs make a right though. The June solstice is astronomically significant for marking the point in the Earth's journey around the sun when the north pole is pointing most directly at the sun. That is, when the sun is beating down most directly on the northern hemisphere above the tropic of cancer. This (not distance to the sun!) is what causes the seasons. But then you'd think the solstice would mark the peak, i.e. mid-point, of winter, not the first day. That always bugged me as a kid. Summer was obviously May through August*, not late June through late September.

Weather-wise, June 21st still isn't exactly the peak of winter because of the oceans. Water stores a great amount of heat and so stays warm for a long time after heating up in the summer. This effectively keeps the continents warm, especially near the coast, a bit into autumn as well. So the solstice is really just somewhere in the first half of summer/winter.

I.e., June 1 is right about the start of the season. And historical averages confirm that June, July, and August are the coldest months of the year in Brisbane.

And by coldest, I mean that the average daily high temperature is around 75 degrees, with no rain. So, you know, why aren't you all moving here yet :)

*Yeah that's four months, not three. Oklahoma has long summers.

Thursday, May 21, 2015

libertarians on climate change

I've been meaning to blog about this and a poll on the facebook page of the Australian Libertarian Society reminded me to do so.

According to the poll, which asked libertarians in the group to answer whether they believe in anthropogenic global warming*, about 2/3 said yes and 1/3 said no. I'd compare that to the overall public but I'm finding a big range of numbers and questions are never worded the same anyway. But it seems similar to the overall right wing opinion, or perhaps a bit higher acceptance, but still drastically less than among climate scientists. I'm interested particularly in libertarians because they are consistently opposed to government intervention in the economy, while Democrats are consistently in favor of it, and Republicans are a pretty mixed bag.

Motivated reasoning is very obviously going on; that's the only way an objective scientific topic could become such a partisan issue. But on which side? Both sides are frequently guilty of it, no matter how often science denialism is defined as an attribute of the right. But on this issue it seems to be abundantly clear that it's only happening on the right.**

A comment on the poll summed up what I believe is the reason the right uses to explain the alleged motivated reasoning of the left: "[It] seems clear that many would like to leverage AGW as a tool for greater government intervention in our lives, massive increases in the size of the state, and subordination to instruments of global governance."

This just makes NO sense to me. If global warming weren't true, why on earth would the left make it up to try to force more government on us? Why wouldn't they use the amount of government they can get away with imposing on us to fix one of the many many real common-resource problems? Why wouldn't they simply exaggerate the dangers of issues anyone can easily verify are problems, and that may even require more urgent action to turn around, like deforestation, the collapse of ocean ecosystems, overpopulation, human rights abuses, etc? Why waste so much energy fighting over the existence of a problem instead of over solutions to undeniable problems? Why would they want to invent a new reason for global governance if the right is already so reactionary to government intervention due to fears of slippery slopes? Doesn't it just give the slope a scarier endpoint?

I don't get it.

On the other hand, libertarians have an extremely obvious reason to deny climate change, just like they often deny other market failures. It's easier to deny the problem than to come up with a plausible nongovernmental solution to it.

A couple weeks ago I gave a talk arguing that behavioral economics does not justify government paternalism, and ended by saying that we libertarians should not take the approach of ignoring solid scientific evidence of mistaken reasoning and arguing the point on this basis. I intended, but forgot, to poke the bear a bit by making the analogy to climate change denialism, which I believe is a huge mistake because denialists have removed themselves from the discussion of what to do about it. Jerry Taylor gets it. The argument for liberty is not (or should not be) predicated on the perfection of markets or the perfection of individual decision-making, and where it is is where I usually depart from the hardliners.


* in effect; the wording was more complicated.

** I should say, I'm sure there's motivated reasoning going on on both sides in the sense that very few people are remotely scientifically literate so most people on both sides are holding much firmer beliefs than they can legitimately justify for the sake of party loyalty. But that only happened after it became a partisan issue in the first place.

Sunday, May 17, 2015

Italy and Switzerland

  6. But Italian is surprisingly decipherable based on Spanish.


  1. It's like Germany, but prettier and more expensive.

Saturday, May 16, 2015

problems with measuring personality

At lunch we were discussing Big Five traits (a common 5-dimensional categorization of personalities, measuring openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism) and this reminded me of the strange phenomenon in my Myers-Briggs categorization that I've noticed over time. In 8th grade I first scored INTP - entirely Introverted vs Extroverted,  strongly iNtuitive vs Sensing,  entirely Thinking vs  Feeling, and borderline Perceiving vs Judging. Nowdays I'm only mostly I and slightly J. I've only taken the Big 5 test recently so I unfortunately don't know the trend, but I assume something similar would have happened.

I don't feel like my personality has changed so this has puzzled me. But now I think I understand the source, and it is concerning with regard to the use of Big 5 in research (mostly in psychology but more frequently as control variables in economics.)

If people are free to maximize their utility of time use,  the marginal utility of any activity should be equal at the bliss point. Obviously we work with many constraints, so I don't expect this to be exactly true*, but I expect it to be closer to true the more freedom of choice we have.

In 8th grade I had no choice but to spend 8 hours a day around people and to follow the strict schedule of activities in general. This was far too much human interaction for me and I would nearly always opt for alone time when given the chance. Nowdays I've carefully engineered my life to have as little compelled socializing as possible, and will usually opt to go to any party friends of mine might have. Similarly,  in San Francisco Matt used to not believe me when I said I was more introverted than him, because I was usually the one wanting to go out and do stuff after work and on weekends. But I mostly worked at home alone,  while he spent 10 hours a day in an open plan office. I would (/did) have a nervous breakdown in that environment.

Along with having more freedom to be alone, I also have more control over my schedule and environment. So while previously the rigid structure and organized environment imposed on me was more than enough, I now realize that I do generally like having a plan and an organized approach to things, hence P became J.

I can't think of what might have suddenly given me more freedom to trade off S/N or T/F, so I'm not surprised those have remained steady.

What does this mean for using these scores in regressions? My first thought is that asking about marginal preferences to measure averages will make people look less variable than they are and will understate the importance of personality. But that's on average. I bet there are plenty of circumstances in which the measure is actually biased.

*but maybe surprisingly close since we should really be equating the marginal present value of activities,  not immediate happiness, which makes work and sleep seem a lot more attractive.

Thursday, May 14, 2015

tourism with economists

We went on a very nice group tour of some botanical gardens yesterday, guided by a sweet old Swiss lady. I don't think she knew what to do with us.

Guide: We don't have any tours in the winter because the ferry doesn't run.
Economist 1: Why not?
Guide: There are no tourists at that time of year.
Economist 1: But couldn't it be that there are no tourists because there are no ferries running?
Guide: [Blank dumbfounded stare.]
Economist 2: This isn't an academic seminar!
All economists: [hearty laughter; muttered discussion on causal mechanisms of tourism.]

Okay, so economists have a pretty terrible sense of humor...

Tuesday, May 12, 2015

awesome broken windows theory tests

This conference on "social norms and institutions", as you might expect, is quite cross-disciplinary. I'm not sure what the breakdown is, but there are plenty of behavioral economists, sociologists, psychologists, and even law professors and political scientists. So, I'm collecting quite a list of interesting new sources from lectures and conversations with these non-economists.

The most fun, and incredible, set of experiments I've learned about are the ones run by Siegwart Lindenberg and Linda Steg and colleagues at Groningen University. Despite having an unusually high prior*, I'm honestly stunned by their results, both in terms of the sheer size of the effects they're finding, and the stability of those large effects across a great number of slightly different situations.

  1. Bikes are parked in a row next to a fence with a conspicuous "no graffiti" sign, and flyers are attached to each bicycle such that they must be removed to use the bike. If no graffiti is on the fence, 33% of subjects will litter their flyers. If graffiti is on the fence, 69% will. This was so surprising that a news station paid the researchers to replicate the study while they watched from rented rooms looking down on the area. The finding replicated very closely, and now the Netherlands requires immediate removal of graffiti.
  2. A temporary fence is set up around a parking lot. Two police ordinance signs on the gate state "no trespassing" and "no locking bikes to fence". People were directed 200 meters around to an alternative entrance, but the gate was left about 50cm ajar. If four bikes nearby were not locked to the fence, 27% of people squeezed through the gap in the main gate. If the four bikes were locked to the fence, 82% did.
  3. In a grocery store parking lot, a sign states "please return your shopping carts", and flyers are left under the driver-side windshield wipers on cars in the lot such that people had to remove them to safely drive away. When no stray carts were left in the lot, 30% of drivers littered their flyers. When several carts were improperly left in the lot, 58% of drivers littered.
  4. Bikes parked in a shed have flyers attached to them as in example 1. In the control condition, 52% of subjects littered their flyer. If fireworks were set off, within earshot but out of sight, which is a well-known offense prior to December 31 in the Netherlands, 80% littered.
  5. An envelope is left partially hanging out of a mailbox and visibly has a 5 Euro note inside, showing through a window in the envelope. In the control condition, 13% of people who passed the mailbox on foot stole the envelope. If the mailbox was covered with graffiti, 27% stole the envelope. If the mailbox was not covered in graffiti but litter was on the ground next to the mailbox, 25% stole the envelope.
  6. A stamped addressed envelope is on the ground next to a mailbox. In the control condition, 24% of passersby put the envelope in the mailbox. If bags of garbage are on the ground nearby (illegal in the Netherlands), 10% did.
  7. A bike is on the ground in an alley, having apparently accidentally fallen off its stand. If passersby have just entered the alley from an empty, clean street, 20% of individuals and 27% of groups right the bicycle. If garbage bags had been left on the street, then 6% of individuals and 5% of groups did so. If prior to entering the alley, passersby passed by someone who dropped an aluminum can and then picked it back up, 34% of individuals and 35% of groups picked up the bike.
  8. A person on the sidewalk accidentally drops some oranges just before meeting another pedestrian. Normally, 40% of passersby help the stranger pick up their oranges. If approximately 20 yards earlier, the passersby had witnessed someone drop an aluminum can and pick it up back up, 64% will help the stranger. If 20 yards earlier, the passerby had witnessed someone (a private citizen) sweeping the sidewalk, 82% helped the stranger.
  9. I can't find the numbers for this one, but in a mall where you have to walk down a hallway to get to a smoking zone, a certain percentage of people will start smoking before they reach the zone. If a group of typical looking Germans are standing around smoking prior to the zone, though, more passersby will light up early. If a group of goth teens are smoking prior to the zone, though, a higher than normal percentage of passersby will wait until they get to the smoking zone to light up.
Amazing. And while each individual study has many issues with interpretation and is targetting a different nuance of the phenomenon, the evidence from all 9 considered together is undeniably striking.

References: 1-8 come from here and here.


* Perceived unusuality is based on my reading of the literature (see next footnote). I've always been sure (without solid evidence) that the mechanism must be quite important.
** This motivated a famous crackdown on petty crime in NYC, which did undergo a drastic reduction in crime, but causality has not been convincingly established and the theory remains controversial.

Monday, May 11, 2015

Swiss regulation

This week I'm at a conference on "Social norms and institutions" in stunningly beautiful Ascona, Switzerland. So there might be a slew of broadly-uninteresting note-like posts on the topic. At conferences and during interesting seminars I usually end up with pages and pages of notes with these idle ponderings, but as long as the apparent norm that laptops can stay open persists, I might as well type them directly into blogger instead...

But first something more concrete, but still on the topic: Going back to this topic of libertarian societies, I previously mentioned that I frequently hear Australia cited as one of the better libertarian countries, mostly due to its fairly small government in terms of spending levels, but that I can't understand how this reputation persists given their intense love affair with regulation. Switzerland is another country that I also hear cited as a libertarian country for the exact same reason. I haven't been here until now and so haven't commented on it, but strongly suspected that the homogeneity of northern Europe that  effectively restricts freedom in Scandinavia, and the love of rules that effectively restricts freedom in Germany, would also exist here. And boy, is that ever true. Within two hours of being here I'd heard three Swiss residents independently joke about how there is a specific rule for everything under the sun. E.g., earthquakes never happen here but once every 300,000 years when the ground shakes a bit, every building will be up to code to withstand a magnitude 9. (Not surprisingly, real estate is ludicrously expensive.)

At dinner, we also all had a good laugh at the regimented approach to managing the buffet. The servers let each table know in sequence when they were allowed to get in line, and when I went up to an empty buffet for seconds and went straight to the end instead of around the "correct" direction, was immediately corrected (in jest, mostly, but it wouldn't have been funny if it weren't based in truth!)

Why?? So, I understand the logic, which is that clear rules ensure smooth functionality. But this logic is predicated on a very skewed belief about homogeneity in preferences. And this false notion of homogeneity is exactly what I think often leads people to support too much regulation*. If there were a more laissez-faire approach to the buffet line, a paternalistic Swiss might view the line as socially wasteful, and might view the first people to jump in line as selfishly impatient, and might pity the ones at the end of the line who only get the dregs from the salad bowl, and he might wish to institute this formal mechanism to correct these ills. But why does he think this will lead to an improvement? People who formerly waited in line were entirely free to remain seated until the line died down, and must have preferred to wait while standing. Those who jumped to the front of the line may have been particularly hungry or particularly concerned about getting a good helping of salad. Different preferences entirely warrant different choices. The formal approach restricts free choice on the grounds that this will solve some kind of public good or externality problem, and I have no idea what makes people think that the laissez-faire approach is so dysfunctional, or that preferences are so homogeneous that free choice is dispensable, to warrant this tradeoff.

Along the same lines, I suspect that a great deal of my aversion to paternalism is due to having pretty oddball preferences in many ways (in addition to an independent aversion to being told what to do in any case.) I'm frequently surprised that other oddballs are so trusting that more regulation will go in their favor, or maybe that they underestimate their oddness or the prevalence of oddness in general, even in the U.S., which has the huge advantage of being so diverse that homogeneity in any dimension is hard to believe in.

*In addition to selfishly wanting other people to behave a certain way that suits me, of course. Ignore that for now.

Tuesday, May 5, 2015

where can I buy insurance?!

I have terrible teeth. Every single year since the beginning of grad school I've both maxed out my coverage and put off major dental work in order to get at least part of it covered the next year. I've lost count of how many fillings I currently have that I've been told "hopefully this'll get you through a couple years, but you really need a crown."

So, I of course want good dental insurance. I'm a good economist though and am not terribly liquidity constrained, so 1) I don't want insurance for the smaller common expenses that I can afford, like cleanings and fillings (or product warranties or renter's or vision or vet insurance). I self-insure for those things by maintaining a savings account. And 2) I only want good insurance because I have private information indicating that I'm a terrible bet for an insurance company.

But I can't buy it! The only dental insurance available that I can find is the opposite of what insurance should be. It covers the first, e.g., $500 of dental expenses per year, and then you're on your own. I want a policy that won't cover the first $500, but will cover any unexpected disasters that push me over that limit. I don't care whether it's an Australian or American company as long as I'm covered in Australia. (No, Australian medicare doesn't cover dental.)

Help? And why don't these policies exist?? I know health care is just about the biggest mess imaginable, but my TANSTAAFL sensibilities are tingling uncontrollably. Why are these mutually beneficial trade opportunities left on the table? Or, what is preventing these trade opportunities from being mutually beneficial, and how can I get around it?*

*I know I just said I'm looking for this kind of insurance because I'm pretty sure it'll be a good deal for me even in a nearly expected utility sense, therefore likely making me a bad deal for an insurance company, but I think I'm on the end of a spectrum there. I'd expect policies to be available that serve the rest of the population.

Thursday, April 30, 2015







Wednesday, April 29, 2015

foster kittens



Sunday, April 26, 2015

programming with dependent types




Part 1: http://talks.bfpg.org/talks/2015-03-24.agda_1.html

Part 2: http://talks.bfpg.org/talks/2015-04-14.agda_2.html

Thursday, April 23, 2015

MOOCs + brick and mortar













Sunday, April 5, 2015

science journalism

More here. (Link stolen from Chris Blattman's blog.)

Thursday, March 19, 2015

libertarian countries?

A few days ago MR addressed an interesting question that I have a great deal of personal interest in: for which country should you vote with your feet if you're libertarian (or social conservative or progressive, but I have less interest in those.) My guess is the United States but with the desperate hope that I'm wrong. Unfortunately, Tyler answers the same.

I could rant in depth about the sadness of this truth, but what really intrigued me about this post was the plethora of comments suggesting alternative answers like Singapore where government spending is only around 15% of GDP*. I don't understand use of government spending as a percentage of GDP as a proxy for libertarianism, at all.

Yes, taxation is the government exercising its monopoly on theft, yadda yadda yadda, but I see that as a necessary evil. I don't feel like my freedoms are being fundamentally violated when the price of doing something is manipulated a bit. I do feel like my freedoms are being fundamentally violated when every 5 minutes I run into another government regulation. Clearly Singapore is very very bad on this dimension, so even if taxes are low, I would rank it very low as a libertarian paradise.

There are two types of laws that I think should be avoided as much as is practically feasible. 1) Nanny laws and 2) preventative laws. Nanny laws are those that try to prevent people from hurting themselves. Preventative laws are laws that make things illegal that might lead to negative externalities if done carelessly or wrong, rather than only making the externality itself illegal. Like, banning dogs in a national park because some people might let their pets attack koalas. I realize that it's often not feasible to rely on only the harm itself being illegal, but regulation in Australia (and the U.S., but less so) is so far from that grey area it's flat out ridiculous.**

So, if my criterion for libertarianism is a commitment to avoid these sorts of regulations, is the US still the answer to the question? Please tell me it's not!

To be clear, snarky answers like "move to Somalia" are not wise enough to be wise-ass. Obviously what I'm looking for is a government of a stable, developed country that chooses to make respect for these freedoms a priority. So underdeveloped countries where the government is entirely preoccupied with more urgent material issues don't count if there's no way of knowing whether they'll adopt a more Norwegian or Texan*** approach as soon as everything else is under control.


*For comparison, the US is over 40% and France is over 55%. Insanity...

**In a cafe a few days ago, I saw a sign on an outlet stating that due to workplace safety regulations, the outlet was not available to customers. My hope when I moved here is that a country this large with so few people must not have too many reasons to regulate every step you take, but based on the nanny state's extent they seem to be expecting half of China to immigrate here soon.

***And yes I'd love to move to a state similar to Texas in this regard, but that set doesn't overlap Matt's acceptable set.

Monday, March 9, 2015

don't argue from premises you know are false

People cling to any facts that help them argue their opinions, and they refuse to admit any downside to their opinions. But tradeoffs are ubiquitous and denying the existence of a gray area, while it may help you feel more confident in your opinion, it makes your argument less convincing. It obviously hurts your credibility when you bury your head in the sand, but more insidiously, it distracts from the fundamental, important reasons why you hold your view.

In other words, if you support X because of A, and someone else opposes X because of B, you can argue that A is more important than B. If you instead argue that you shouldn't oppose X because B isn't true, anyone who believes in B will ignore you completely and miss the more important issue of A. But people do this even when the evidence overwhelmingly suggests that B is true!


  1. I suspect that making immigration to the U.S. will hurt the wages of some low-skilled Americans. But I favor freer immigration anyway because it's overwhelmingly clear that it will make people better off on average, and therefore it's the right thing to do if you care about humans equally. By fixating on small findings that show that in certain special circumstances, unskilled labor immigration helps unskilled American laborers, you allow yourself to be dismissed as soon as any contrary result (which will surely turn up) is found.
  2. I suspect there is probably some health cost to smoking marijuana. I support its legalization anyway, because I strongly believe people should be allowed do whatever the heck they want that doesn't hurt anyone else. Arguing that marijuana should be legal because it's safe undermines this more important issue and, if this argument becomes widely accepted, it will undermine other arguments for legalization of activities that pretty obviously do have (victimless) costs.
  3. I'm pretty sure that increasing the minimum wage will usually reduce overall employment. I don't support minimum wage increases, but for those who do, take note: I can't take you seriously when you claim that the law of supply and demand doesn't apply to labor. It may be true that in certain special circumstances minimum wage increases won't have this effect, but I'm guessing you don't want to restrict minimum wage increases to those scenarios, so stop fixating on those iffy findings as the basis of your argument.
  4. I have no idea what the nature/nuture breakdown is on homosexuality. Nor do I care, when it comes to politics. Equal rights for non-heterosexuals is the right thing regardless of whether sexual orientation is chosen or occurs from birth. Saying "I didn't choose to be this way, so don't discriminate against me!" gives your opponents an opening they shouldn't have: to fixate on any minor correlation between sexuality and upbringing as evidence of choice.
  5. I am an environmentalist not for economic reasons. When we figure out ways to thrive as a species without the natural ecosystem, I will still be a conservationist, because this (sort of, if you can call that a reason). So while in many situations conservation can be easily motivated by economics, I don't want to fixate on that logic because I also want biodiversity and wild lands and beautiful landmarks to be preserved purely for their own sake even if someone managed to argue that it would be worth more in dollars to convert one to a mine.
  6. I'm sure that global warming is happening and that it's causing major problems (already, yes). If you don't like certain political solutions to these problems, then argue why. Don't just deny the problem. It makes you sound crazy. It also immediately cuts you out of the decision making process because everyone trying to address it disagrees with your entire premise that the phenomenon isn't real.
  7. There are all kinds of nutty inconsistent things in the Bible. I couldn't care less. By arguing about them, I imply that I'm not religious because of some contradiction in a particular text, which allows any religious person to dismiss me immediately by coming up with an alternative way to interpret that contradiction (or an alternative text to believe in).
The list can go on infinitely of course.

I understand the temptation of these arguments. If someone objects to opening borders because it will hurt unskilled Americans, it's hard to change the topic entirely to fundamental human rights. We respond to immediate sub-issues. And why do we cling to facts that might be useful in those irrelevant side issues? Because we cling to any facts that make our views a lighter shade of gray.

The truly puzzling thing about this phenomenon is that we continue to do this even when we scoffingly dismiss people who do so on other topics. Democrats scoff at Republicans who claim that tax cuts increase tax revenue based on the Laffer curve, but then they claim minimum wages increase employment based on the equally tenuous finding that in some strange circumstances, however rare, that might be true. I guess I'm forced to conclude that motivated reasoning is so powerful that we don't even realize how selectively we interpret facts and how black and white we're pretending things are.

Sunday, March 1, 2015

ethics reviews gone wild

My next door office neighbor, Paul Frijters, is in the news right now due to being ridiculously harassed over alleged unethical experimental methods. The study used RA's of different races to try to board buses with empty fare cards in order to examine whether drivers are more likely to let white and east asian people ride for free (they are). At issue is whether it is ethical to "defraud" the transit system in such a way.

Note that the RA's did not request a free ride. It was entirely up to the busdrivers how to respond to the RAs having an empty card. And of course the transit system didn't lose any money from the study in the first place because these RAs wouldn't have been taking these 2km rides at all otherwise... But most importantly, the study went through the proper ethical clearance channels and was approved. It's abundantly clear that the reaction of the transit system to the proof of some degree of racism is the only reason the University reacted the way it did. Politics.

Not only do I wholeheartedly agree with Ian Ayres's defense of this research, this incident should be raising enormous red flags about the ludicrous state of ethical clearance for economics research. In so many cases, it serves not to protect the subjects but to cover the asses of the university in the event of any controversial press, especially that which incites ill political will.

This on top of the fact that social science ethical clearance was designed in the tradition of medical research ethical clearance, and is often still handled by the same people, so that the obvious and significant risks inherent to biological testing are looked for in completely benign games that economists have their subjects play in order to study decision making. We've gone from one extreme in which the Milgram and Zimbardo experiments can be run to another extreme in which experimenters aren't allowed to sell things on ebay because people might regret their purchases. And if they eventually can, it's after months and months of back and forth and wasted time dealing with internal review bureaucracies.

Social science is suffering. Australian social science, even more than U.S. social science, far more than European social science*, is suffering. It's time to streamline the ethical review process and bring some common sense back.

Update: I should probably point out*** that despite being affiliated with UQ, I do not speak on their behalf, nor do I know anything about Paul's case other than that which was publicly reported, and all is not said and done. Regardless of what mess of details is involved, however, I 100% support the research program as important and ethical and 100% stand by my assessment of IRBs having gone completely off the rails. The latest anecdote I hear is of a project that was denied because the results might be used to make money. Welp, I guess all of science can call it quits; our job is apparently inherently unethical...


*Internal review boards don't even exist in Switzerland. Doesn't matter - unethical research has no chance of getting published so self-regulation works well, in the same way that economists sustain much better experimental practices than psychologists. But you do see particularly cool studies** coming from Europe :)

**Before you start objecting that killing mice is actually unethical so clearly IRBs are needed in Switzerland, read further. The researchers took research mice that were slated for killing already and gave people the option to pay to save their lives. Armin Falk is now taking care of some of the most spoiled mice in Europe as a result. It was not possible for any mouse to be worse off as a result of the experiment.

***It has been gently pointed out to me, by a few people actually, that Australia does not guarantee freedom of speech. (Or privacy. Don't get me started.) I knew that but I think I'm going to continue taking the enormous risk of blogging for all two dozen of my readers :)

Wednesday, February 25, 2015

the rationality of heuristics

I recently joined a very interesting reading group and we're working our way through the new book "Evolution and Rationality: Decisions, Co-operation and Strategic Behaviour". The discussion about chapter 5 (by Brighton and Gigerenzer) was very thought-provoking. The chapter discusses the difference between "small world" and "large world" problems. The former are problems in which we are certain of the underlying processes, such as playing roulette. Large worlds are too complicated to be certain of the underlying probabilistic processes, perhaps too complicated to be certain of which processes are relevant at all, and the whole thing may not even be stationary. For example, playing the stock market.

The gist of the paper is that trying to model behavior in large worlds by deriving the optimal, rational thing to do, is misguided. This approach works well in small worlds but in large worlds it's highly likely that you'll specify the problem incorrectly. Heuristics can work better than complicated statistical bayesian reasoning. There's a great example of guessing which of two German cities is larger, based on a vector of attributes such as whether it has a university, whether it's on a river, whether it's located in the industrial belt, etc. In this case, a simple take-the-best heuristic, which looks only at the most relevant attribute that can distinguish between the two towns in question, outperforms an SVM.

This is a strong statement: not only can you understand actual choices better if you allow yourself to consider non-bayesian agents, you may understand what is actually optimal better.

I'll say that again a different way because I think it's that important: When we observe people behaving in a way that seems suboptimal, we should not infer that people are violating the rational/bayesian/vNM agent model. We should first question whether we truly understand the problem as well as we think we do.

This means that one very common response to psychologists' claims that people are non-(Bayesian/vNM/rational) by economists who are trying to rescue homo economicus, while clearly true in many cases, is sometimes not even necessary to resort to. In particular, heuristics are often seen to be rational because they are the optimal balance between mental calculation costs and accuracy. As the German city example proves, heuristics may in fact be a better approach to large world problems than a more sophisticated statistical analysis.*

Heuristics therefore definitely belong in the basket of reasons behind one of my favorite soapboxes: respect revealed preferences! Behavioral economics is too often seen as an excuse for all kinds of intervention in choices in order to "help" people optimize. But trying to do that is problematic for all kinds of reasons, including that it is very hard to prove that people are actually making mistakes. Observing demand for commitment devices is one of the rare cases where we can definitely say that restricting the choices of some people would make them better off. Such clear cases are few and far between.**


*My other objection to this frequent assertion (which I do believe is true in many cases, just not so many) is that critics of economics don't understand that most economic models are "as-if" models, and many economists have started to forget it, probably partially in response to all the negative press about classical economics that fixates on the implausibility that people actually make the calculations we model. But predicting the trajectory of a baseball is difficult to calculate, yet humans instinctively can do it very very well. Predicting the trajectory of a frisbee in gusty wind may not even be analytically tractable but somehow humans can do it reflexively. So why is it so hard to believe that humans are as good at optimizing their utility as they are at optimizing their frisbee catching? High mental calculation costs are not implied by analytically complicated problems.

**Not that situations in which people can be helped are rare, but situations in which we're sure there is room to help, and that by trying we won't make things worse, are rare.

Tuesday, February 17, 2015

retention in online education

I'm nowhere near a labor economist but in another life I would study education. Online education is particularly fascinating to me since I personally love it. I've done 8 or 10 coursera classes and started and abandoned about as many more. I love being able to learn about new subjects in a structured and multi-faceted* way again; it's like being able to take all the exploratory freshman college courses you want.

One of the first reasons people dismiss online education is something I wish wasn't a valid reason but I understand why it is. There's a major barrier to it being taken seriously as a credential, which means it's not going to be a substitute for traditional education anytime soon and will have trouble being financially viable.** But, as long as these credential-free courses exist despite lack of lucrativity***, I think that's great! They're purely about learning (what a concept!). The people in the course are self-selected based on genuine interest. The message boards consistently contain more fascinating and in-depth discussions than anything I've encountered in actual college classes. If I'm too busy one week, I'll skip a homework set, do it later at my leisure, my "grade" will suffer, but who cares.

I've lately heard a couple people dismiss online education for a reason I think is more bizarre, though.**** Retention rates. Yeah maybe it sounds bad when you excitedly advertise your course as having 700,000 signups but then have to later admit that only 10% of them completed it, but signups shouldn't be the metric in the first place. One of the great things about online education is that it's easy to peruse, test the waters, watch a few videos, try a couple weeks of homeworks, and then quit if it's not what you're looking for. Only one class that I've quit has been because I got too busy with other things and let it slide; the others were all because I made a conscious decision that it wasn't worth my time. Low retention rates (on average) is exactly what you want if what you care about is actual learning rather than credentials. If a particular class has a high retention rate that's a good sign about the quality of the course, but if retention rates are high across the board, people probably aren't exploring enough or are disproportionately motivated by the sheepskin.


*Structured meaning that each lecture builds on the last, allowing you to get to deeper truths vastly more easily than trying to piece together 30 isolated wikipedia articles. And multi-faceted meaning not just reading a book, but actually going through problem sets and taking quizzes and such. Highly important for information processing and retention.

**Coursera is falling over itself to change this; you can now often pay to get a "verified certificate of completion" instead of the standard free pdf download, or you can get a special certificate "with distinction" if you achieve a certain grade, etc. I have no idea if these are helping them make money yet but that's obviously the goal.

***Which I'm sure won't last forever; right now it's driven by a lot of excitement and curiosity and altruism but that won't sustain it once it's thoroughly clear that the current model won't make money. But hopefully the huge body of work that has already been done can be recycled indefinitely.

****Sort of like people dismissing charter schools because they're, on average, performing worse than traditional schools. That's exactly what should be expected!