Saturday, February 27, 2010

OK, rats or monkeys maybe- but pigeons?!?

Via Marginal Revolution, this totally blows my mind:

"Are birds smarter than mathematicians? Pigeons (Columba livia) perform optimally on a version of the Monty Hall Dilemma

Walter Herbranson & Julia Schroeder
Journal of Comparative Psychology, February 2010, Pages 1-13

Abstract: The “Monty Hall Dilemma” (MHD) is a well known probability puzzle in which a player tries to guess which of three doors conceals a desirable prize."

If you aren't familiar with it, the Monty Hall problem comes from the game show "Let's Make a Deal." In the game, contestants are presented with three numbered doors. A desirable prize is behind one of the doors, while behind the other two doors are undesirable booby prizes like a goat, a bale of hay, etc. The contestant chooses one of the three doors. Monty Hall, the host of the show, then opens one of the remaining two doors to reveal one of the booby prizes, leaving the constestant's chosen door and one other door. The contestant is then given the option of switching to their choice to the other closed door, or sticking with their original choice. Most people incorrectly reason that it makes no difference. In fact, if you stick with your original door your chance of getting the desirable prize is 1 in 3, whereas if you switch it's 1 in 2 (the key is that the door Monty picks to open is always one that has a booby prize behind it). I took a statsitics class with one of the smartest people I've met in which this example was presented. She was completely fooled by it and actually stayed after class to argue with the instructor. I certainly had a hard time wrapping my head around it the first time I saw it. And yet apparently, pigeons are not fooled:

"... a series of experiments investigated whether pigeons (Columba livia), like most humans, would fail to maximize their expected winnings in a version of the MHD. Birds completed multiple trials of a standard MHD, with the three response keys in an operant chamber serving as the three doors and access to mixed grain as the prize. Across experiments, the probability of gaining reinforcement for switching and staying was manipulated, and birds adjusted their probability of switching and staying to approximate the optimal strategy. Replication of the procedure with human participants showed that humans failed to adopt optimal strategies, even with extensive training."

Why are documentaries that deal with economic issues so lousy?

Documentary films that tackle economic issues are ovewhelmingly oversimplified, one-sided polemics, usually (but not always) from a far-left kind of perspective. Rarely is any attempt made to present the issues in anything resembling an objective way, or to let the audences make up their own minds about things. The filmmakers have a clear message that they are advocating- usually something along the lines of, "______ is really, really bad!"- and the film is an attempt to hammer home that message. Examples include Roger & Me, Life and Debt and The Corporation . That's not to say that these films don't have any merit at all- I actually like Roger & Me quite a bit, and Life and Debt is certainly worth watching- but there's no denying that the perspectives are one-sided and polemical.

Why is this? You might argue that these films have to be that way because audiences are stupid and they don't like things to be complicated. But that doesn't really explain it, because there's another more popular genre of documentaries where the norm is exactly the opposite. I'm thinking of character studies, like Tyson, Crumb, or Grizzly Man. The intention is these films is quite clearly to unpack the complexity of their subjects in a way that often seems to conciously promote ambiguity- a film like Errol Morris' The Fog of War, for example, wants you to see the different sides of Robert McNamara, appreciate the context and significance of his actions, etc. It's not trying to convince you that McNamara is "good" or "bad," in fact sometimes it feels like it's trying to prevent you from drawing too strong of a conclusion one way or the other.

All else being equal, you'd think the audience for documentaries about economic issues would be at least as smart as the audience for character study type documentaries- so why are the ones about economic issues so much more simplistic?

My only theory is that there may be some sort of path dependence. There are only a limited number of movies that are going to get made, so the outcome is not going to look like a competitive market. It may be that audiences have just come to expect movies that deal with these kinds of issues are going to be lefty polemics, and a film that took a different approach would have to struggle to overcome this perception.

Thursday, February 25, 2010

Bayesian Learning

I'm a huge fan of Bayesian learning. I don't try to figure out the right answers, I try to figure out what all the possible answers and assign probabilities to each one. When I get new information, I update my probabilities based on how credible the information is, and how strong my prior beliefs were. For example, a while ago I did some reading about how laws that allow people to carry concealed handguns affect violent crime. Beforehand, I would have said there's about a 5% chance that concealed carry laws reduce violent crime, a 60% chance that these laws increase crime, and a 35% chance that it doesn't make any difference.

The stuff I was reading was at Econ Journal Watch, which was neat because it allows the authors of various studies that contradict one another to go back and forth; I looked at some other things as well. In any case, I found one (gated, unfortunately) paper that presented what it claimed was strong evidence that concealed carry laws reduce crime, and then a bunch of other papers that poked holes in it. Much of the hole-poking was legitimate, but it was the sort of hole-poking that suggests that maybe the coefficients were smaller or less significant, rather than the sort of hole-poking that suggests fatal flaws. It would be very difficult to convince me that concealed carry laws really do reduce crime, but what I read was enough for me to update my beliefs substantially. I'd now say there's about 10% chance that concealed carry laws reduce crime, a 15% chance that they increase crime, and a 75% chance that it doesn't make any difference. My priors updated and my Bayesian learning for the day complete, I happily resumed my regularly scheduled activities.

But some people would approach this kind of thing in a very different way- from what we could call a "Working Hypothesis" perspective. Such a person with similar underlying views as mine were at the beginning would instead take as the starting point, "I believe concealed carry laws reduce crime," and then they would act as though this hypothesis were true. When presented with new evidence, they would either a) interpret the evidence as not strong enough to overturn their working hypothesis and reject the evidence, or b) interpret the evidence as strong enough to overturn their working hypothesis in which case they would switch their belief to "I believe concealed carry laws increase crime" and proceed to go through life as though that hypothesis were true.

It's fairly obvious how in many instances a Bayesian Learning perspective would lead to better decisions than a Working Hypothesis perspective. But my question is, is there any circumstance under which a Working Hypothesis perspective might actually be preferable? Or is it just plain worse?

Wednesday, February 24, 2010

New website

My new website with info about my work and other stuff is here.

Also if anyone is looking for help designing a similar type of site I would highly recommend Dan Dumitrescu, the freelancer I used for mine. He's reasonably priced, fast and reliable, and does nice work, you can contact him at

Sunday, February 21, 2010

While you were out...

... apparently there was a coup in Niger.

The international community responds by suspending aid; The Center for Global Development's Jenny Aker argues that might not be the best idea:

"There are both legal and theoretical reasons for cutting off aid after political instability. Legally, the U.S. State Department is bound to suspend aid if a coup occurs... but reality is quite complex. After drought and pest infestations last year, Niger is currently in the midst of a potential severe food crisis... If the military does remove Tandja from power, it will take some time for them to set up elections; in 1999, elections took place six months after the April coup. But the people of Niger can’t wait six months."

I agree in the main, and would also point to the question of what cutting off aid really accomplishes. Is the threat of all halting donor-funded development projects really supposed to hit the coup plotters where it hurts, or deter coups is other places in the future? Or is it just an empty way of putting an exclamation point on the international community's collective expression of disapproval?

Niger has entered into a couple of high profile oil and uranium deals with the Chinese government and a French parastatal recently. Instead of suspending development projects until they hold elections, how about banning mineral imports from Niger instead?

Saturday, February 20, 2010

Findings from the ISAs

I've just spend three days at the International Studies Association meetings in New Orleans. I was hoping to make some interdisciplinary buddies here so that we could do interdiscplinary activities together, such as walking and chewing gum at the same time, or perhaps creating a unified theory of the social sciences. Sadly, I was not successful in this. I believe this was because the meetings ended up not being so interdisciplinary at all, the participants were overwhelmingly political scientists. In hindsight maybe my approach was off- I think I could have generated more interest if I had pitched it as spatial recontextualizion of identities and gum at the same time.

In any case, having been at the American Economic Association meetings in the exact same hotel a couple of years ago, I have undertaken an empirical analysis and have three statistically significant findings to report:

1) Political scientists are nicer, more normal people than economists. No surprise there.

2) Political scientists dress way better than economists. This is also no surprise, but it's much, much more dramatic and pronounced than I would have expected. I had thought the majority of the populations in all academic disciplines would be sort of nerdy, but some of the panel sessions I went to, I felt like I was at the Black Cat.

3) Economists have much better presentation skills than political scientists. This surprised me, I would have expected the opposite. My working theory is that being socially maladjusted weirdoes, many economists have realized that when they just be themselves, other people tend to run in the other direction. This makes them understand that they're going to need to put significant thought and effort into their approach if they're going to communicate with others, which leads to good presentation skills. By contrast, a lot of political scientists think they can just get up there and be their well-dressed, hipster selves, and everything else will take care of itself. Often, though, it doesn't. If you don't want to give a typical Powerpoint presentation, that's fine- but at least preparing a few slides or a handout to keep your audience focused is ALWAYS a good idea. Also, reading a prepared script out loud does not make for an effective presentation. I have never seen an economist do that, but I was stunned to see several political scientists do it this week.

On a more substantive note, I was struck by just how much empirical work goes on in political science in the panel sessions I went to. Granted, those were the kind of panel sessions that I tended to gravitate towards, but still- it seems that analyzing data is not some weird, fringe-y activity in political science these days. I was also struck by what I perceived as the strengths and weaknesses of the research findings. When I go to an economics conference, I am typically impressed by the methodological tools that people are using, but pretty underwhelmed by how relevant or interesting their research questions are on the whole. I can't really point to much that's wrong with what people are doing, but I often wonder why they'd want to do it in the first place. What the political scientists were doing was exactly the opposite- all of the issues people were looking at were fascinating. But most of the empirical approaches had pretty glaring flaws, and not just because of the data or whatever, but clear methodological problems that were easy to identify. I've blogged before about the different standards in different disciplines, and the standards for what constitutes a "result" in political science is quite low relative to economics.

Ultimately it seems that there is a lot of untapped potential for collaboration between economists and people from other social sciences on this kind of stuff. If you give them a question, economists have a comparative advantage getting as much mileage towards answering the question as the data allow- your average economist is head and shoulders above your average quantitatively-minded political scientist or sociologist in this regard. But, quantitively-minded social scientists in other disciplines are asking a lot of interesting questions, and asking the interesting questions is something that I don't think the discipline of economics does very well or values as much as it ought to.

Tuesday, February 16, 2010

Extremely Negative Psychology

This came in the mail today, I've been giggling about it all evening. It's been a very long time since I've been this interested in any subject not related to development economics or Africa.

My current understanding of evolutionary psychology is this: our brains have evolved into finely-honed machines that are geared towards making us good at being cavemen. By good I mean, good at spreading our genes, good at surviving and reproducing. This presents us with two problems, one obvious, the other less so. The obvious problem is that we are no longer cavemen. The pace of change in human society over the past 200 years has been too rapid for our evolving brains to keep up. The sorts of traits that are desirable in modern societies are quite different from those that were desirable in pre-industrial societies, but our brains are geared towards the caveman stuff.

The less obvious problem is that being "good" isn't really what we care about after all. Instead, we care about being happy. But the unfortunate reality is that our brains have not evolved to maximize the happiness of people like us in the information age, they've evolved to maximize the fitness of cavemen. Ultimately, happiness is nothing more than a tool that our brains use to manipulate us into doing the things that allow cavemen to spread their genes. And it gets worse- the brain doesn't want us to be happy, it wants us to pursue happiness. The brain doles out pleasure and satisfaction when we increase our status, accumulate more resources to impress mates or protect our children, and punishes us with anxiety and misery when lose status, or fail to attract a mate or protect our children. But the reward is rarely as good as we think it's going to be, because our brains don't want us to rest on our laurels. They want us to go out and get more.

Anyways I am thinking of starting an academicky movement around these ideas with sinister, cult-like overtones, similar to the Postive Psychology movement. Only I'm going to call mine the "Extremely Negative Psychology" movement. My first book will be called Damn You, the Human Brain!

Any joiners out there?

Monday, February 15, 2010


I'm heading off the International Studies Association conference in New Orleans next week. Now, I'm a pretty interdisciplinary guy- I teach interdisciplinary classes, my job is half in an interdisciplinary program, I have interdisciplinary people I hang with. But when it's time to throw down and get rowdy, researchwise, I'm all economist, all the time. I've never actually collaborated with someone from another discipline, and the amount of stuff that I read from other disciplines is limited (though growing). As a result, my conception of People From Other Disciplines is limited to a binary classification system consisting of Good Guys, and Bad Guys. I have worked out that Good Guys are most likely to be anthropologists, though it's not necessarily the case that anthropologists are most likely to be Good Guys. In case any of you People From Other Disciplines were might be wondering which camp you fit into, I have prepared a handy list of clues; note that the list is not exhaustive, and just because a particular clue applies to you doesn't automatically make you a Good Guy or a Bad Guy:

  • Good Guy clue: Your work generates substantive claims that could (in principle at least) be tested and either verified or rejected
  • Bad Guy clue: Your work generates lots of new vocabulary words, which often begin with "re," "counter," or "post"
  • Good Guy clue: Your work contains more references to your subject matter or related analytical concepts than it does to things other academics have written
  • Bad Guy clue: You spend a lot of time refuting "alternative positions" that consist of cariacatured views that no one would ever actually hold- your formidable fangs are dripping with the blood of the strawmen you created in Section I!
  • Good Guy clue: You are not afraid of quantitative data, most of your papers probably even have some in it
  • Bad Guy clue: You use the words "discourse" and/or "neoliberal" alot
  • Good Guy clue: A policymaker or donor who is interested in doing a good job would (or at least should, and you can claim this with straight face) be willing to pay you for your expertise
  • Bad Guy clue: The only conceivable circumstances under which anyone from outside of academia would ever be willing to pay you for anything would be to make you stop talking and leave them alone.

Anyways, here's hoping I will come home from the conference with my horizons broadened and my views more nuanced... and not in a homicidal rage muttering about reconceptualizing post-colonial neoliberal discourses or something.

Public health vs. economics: disciplinary standards and political economy

Different disciplines hold themselves to different standards when it comes to how strong your empirical evidence has to be before it constitutes something that you can claim as a "result." By result I mean you can start telling everyone else about it, publish it, etc. One such distinction that intrigues me is the one between economics and public health. Relative to economics, public health has very low standards. This is particularly the case when it comes to dealing with what public health people call "confounding factors," which is part of what economists would call "endogeneity." Put simply, this is the idea that if you observe some correlation between A and B, it may be the case that there is a C that you didn't account for that is driving your results. For example, I remember reading a study one time that linked cigar smoking to cirrhosis of the liver. Someone pointed out that it was much more likely to be the case that alcoholism causes cirrhosis of the liver with a high probability, and that cigar smokers are marginally more likely to be alcoholics compared to the rest of the population, as opposed to that cigar smoking actually causes cirrhosis of the liver. But, this finding is good enough for a result that you can publish in public health. And it's not just the journals- public health results that seem very likely to have been driven by spurious correlation frequently make it into the newspaper: I read recently that coffee might prolong my life. You'd never get away with that in economics. In order to publish anything, you need to go through pretty intense statistical machinations to deal with even the merest hint of confounding factors.

This is not a knock on public health, as there is no independent reason why a higher standard is better. You can never account for all of the potential confounding factors (or other problems); no empirical research finding is 100% iron clad. So the question is simply what constitutes "good enough," in the sense that your result is worth being considered as part of literature and included in further discussions of that topic. Too low of standard and the debate will be polluted by evidence that isn't really evidence, but too high of a standard and you will exclude important and relevant research from the discussion.

What I find strange about this is that there is no reason why public health should have a lower standard than economics. In fact, if anything it should be the other way around. The data in public health studies is often as good as data can get; you can hold that data to a higher standard. Not to mention, it seems to me that before we start telling people what's going to kill them and what's going to prolong their lives, we ought to be really sure we know what we're talking about. A spurious correlation between coffee drinking and longevity is not something that we should be putting in the newspaper.

Conversely, economics is by nature a less exact science. We know a lot less about what we're talking about than public health people do, so we need to be more open to the possibility that we're wrong in any given case. The data we work with are also much worse (particularly in development economics). It would seem to follow that a greater degree of statsitical dubiousness should be acceptable, but it's not. For example, suppose an economist came up with a finding along the lines of, "A looks like it does lead to B, but my data isn't very good and there are plenty of reasons to doubt the relationship. But if A did in fact lead to B, that would have important implications for Theory X." That would never make it into a good economics journal, let alone the newspaper. Yet, it seems to me something along those lines could be very much relevant when it comes to contributing to economists' understanding of the world.

So what explains the discrepancy? The only explanation I can think of is political economy- i.e., what's in the interests of the practitioners of the discipline? I know less about public health, but it seems that public health studies tend to have lots of money and big funders behind them. The funders want results, and they want these results publicized. A lower statistical standard gives rise to more tangible results that you can claim in order show the funders that their money is being put to good use. The practioners of the discipline on the whole benefit from a lower standard because happier funders means more grant money in the long run.

In economics, by contrast, grants are not what makes the world go round; different incentives are at work. Over time, the discipline has become more and more technical and mathematically sophisticated, which functions as a barrier to entry- a higher degree of mathematical sophistication means fewer people are willing or able to get a PhD in the subject. This barrier to entry has been very effective, as unlike almost all other academic disciplines the supply of PhD economists does not far exceed the demand for them. The unemployment rate among PhD economists is close to zero, and economics professors get paid in the neighborhood 30-40% more than people in other social science disciplines. Maintaining higher standards of statistical rigor reinforces this barrier to entry- producing a result that economists find worthwhile requires you to put your years of difficult and/or painful training in econometrics to use. Hence, economists as a whole benefit from maintaining the higher standard because it helps to keep the labor market tight.

Can anyone think of another explanation?

Thursday, February 11, 2010

The African Union and the generation gap?

The Economist tells the African Union to get tough:

"The AU has done distinctly better than the OAU. It has more or less stuck to its charter forbidding countries whose leaders take power in military coups from becoming members...yet there is still a woeful reluctance in Africa to chastise, ostracise or help to oust villainous leaders... its failures go back to Africa’s age-old problem: too many of its leaders, out of a misplaced sense of post-colonial solidarity, are loth to criticise their peers, however vicious."

High hopes surrounded the AU when it was formed in 2002, and I think it's safe to say that in terms of promoting good governance most would view the results as disappointing. But I'm not sure what we could have realistically expected. That "mis-placed sense of colonial solidarity" may be a little bit more firmly entrenched than the tone of the Economist article suggests- perhaps one legacy of colonialism is a reluctance to be too heavy-handed about telling other African leaders how they ought to behave. Most of the current African leadership came of age in the wake of de-colonization, and their views are often heavily colored by thinking in terms of colonialism and independence (if you've ever had a conversation about politics with an African elite over the age of 60, you probably know what I'm talking about). So maybe it's not so surprising that an inter-governmental organization run by these guys would tend to view its mandate as limited.

In that vein, it will be fascinating to see what happens over the next 10-20 years as the next generation takes over both with the AU and more broadly. The new African elites will not be looking through the same post-colonial lens, and that could mean big changes in terms of how African countries relate to one another, and the West.

Tuesday, February 9, 2010

The US news media does a great job of covering Africa!

It's true!

Media coverage of Africa and development issues in general takes quite a lot of flak from bloggers, and rightly so I believe. So, let's give credit where credit is due: The Christian Science Monitor recently ran a piece by Jina Moore, entitled "Africa's Continental Divide: Land Disputes." From the standpoint of tackling complex and multifaceted issues without oversimplifying or dramatizing them, this is one of the better newspaper features I've ever seen:

"Land, at the very heart of security and survival, looms behind most of the African conflicts we've all heard of and dozens of others we have not...

Fixing the land problem may lay the foundation for fixing so many others, from poverty to famine to ethnic conflict. If farmers feel their claims to plots are sound, if social groups feel land policies are impartial and just, and if women and men have equal rights to the soil, experts say Africa's other ills will be easier to treat...

A good way to understand the roots of Africa's land dilemma is to drive through rural Sierra Leone or Liberia. Cratered dirt roads cut through what feels like limitless, untouched land: Stately palm trees and skinny rubber trees sway over miles of tall, tangled grasses. Along the road, people walk with the day's laundry or firewood on their heads – moving, one assumes, from the cluster of mud huts that make up the village just behind to the cluster just ahead. But to the left and right of the road is what the colonists called "virgin forest."

It isn't, of course. And even a stranger should know better: A husky, sharp scent wafts over the road, like burning buttery popcorn: someone deep in the forest is making palm-kernel oil. Or, just a 100-foot trudge off the road, through shoulder-high elephant grass, the sounds of what's hidden can be heard: Rice farmers splash through swampland as they harvest; cassava growers sing to themselves as they slash through last year's tangled weeds readying the ground for this year's crop. Deep in the woods that seem wild and untouched to outsiders, people live and work as they have for hundreds if not thousands of years."

My only complaint is that I don't think she adequately fleshes out the dark side of customary systems:

"ACROSS AFRICA, INDIVIDUALS... and even entire communities, are brokering their own solutions to land conflict. Sometimes those solutions require people like Elaine Kamue. A short woman with a soft voice and a blunt way of speaking, Mrs. Kamue travels from village to village in rural Liberia, educating women about the country's new land laws – and intervening to help put the laws into practice.

Without Kamue, 55-year-old Yar Gegh would be homeless and starving. For years after her brothers had left sleepy Zuluyee, a roadside market town a few hours from Liberia's border with Guinea, Ms. Gegh remained to farm the family plot and care for her dying mother. She had, she says, little choice: "Only a woman can mind her mother."

In 2005, her oldest brother, Lawrence, came back to the village and kicked her off the family land. "He say, woman didn't own land. Woman didn't get property," she recalls. "He beat me. He [insulted] me and dragged me on the ground." The abuse and insecurity became so bad, Gegh fled from Liberia to Guinea, at a time when thousands of Liberian refugees, ready to try out life under a new, democratic government, were making the opposite trip.

Mr. Gegh admits he pushed his sister off the family land: "I told her, 'I'm here now to take care of the area,' I was a soldier-man. I was a military person. I came to take charge of the post."
Four years into the dispute, they found a solution when Kamue came to town. Kamue, who works with the local Catholic Justice and Peace Commission, a chapter of an international nongovernmental organization that works on social reforms at the grass-roots level, told Gegh about the new law. She explained her conflict with her brother, and Kamue offered to mediate.

"It took four hours," she recalls of the one-on-one mediation that usually takes an hour. Mr. Gegh agreed to give his sister a small plot to farm for food, and she invited him to live in a room in the house she'd built in town."

I don't think the lesson of this story is that communities are brokering their own solutions to conflicts. Rather, it's that customary systems have losers too- generally women, minorities, and migrants. One the most important justifications for interventions in tenure issues by governments, NGOs, etc. is to try to get these people a fairer shake. Yes, any formal property rights system must involve a high degree of local control and take cognizance of what's already there. But formalizing the informal system isn't always the right answer.

A minor quibble with what is overall an excellent piece.

Thanks to Texas in Africa for the pointer.

Sunday, February 7, 2010

In the Loop

British political satire. The premise: the politically incompetent head of an unimportant government department is thrust into the spotlight when he says the wrong thing in a radio interview. Which department do the filmmakers pick as the emblem of unimportance? International development, of course, ha ha ha. That's about all the movie has to do with development, but it's hilarious, particularly if you've ever worked in government. The style of humor is so dry it sucks the moisture out of the air. An important takeaway for me was that someone screaming profanity in Scottish accent is almost automatically funny.