Who you gonna call? A mob

stoning

“Look, I’d had a lovely supper, and all I said to my wife was: “That piece of halibut was good enough for Jehovah.” “Blasphemy! “”

Large crowds are inherently scary. Not, perhaps at first glance, but those of us that live in large cities do so under the assumption that while crowds are somewhat chaotic  and have the potential for danger, they will never be intentionally malevolent, at least not towards us. Yet there is still an unease there, of the type that underlies the kind of horror frequently employed in post-apocalyptic zombie films or John Carpenter flicks, that very quickly the crowd can turn against you.

Perhaps this is not totally unreasonable source of anxiety – while most violence in London (where I’ve recently started living) tends to be of the individual-on-individual sort, mob violence is more frequently a reality for many living in developing countries. Take, for instance, this new report by the incredibly prolific NGO Twaweza on violence in Tanzania. Drawing upon a nationally-representative phone survey, one of the most striking results is deaths due to mob violence appear to be more common (or are as commonly-perceived by respondents) than ordinary murders: twaweza

In fact, as many people are killed by mobs as by ordinary citizens, police and the national army combined. If we consider mob violence to be a form of extra-legal justice, imagine a government which executes more people than those who commit murder. While these figures are based on perceptions and should be taken with a grain of assault, it’s worth noting that forensic investigations into violent deaths in Dar es Slaam reveal that at least 10% are due to mob justice, still a staggering number.

Yet, outside of the occasional hushed ex-pat dinner party conversation or resigned lamentations by locals, I’ve rarely hear people actually discuss the causes and consequences of mob violence in much detail (although as I write this I suspect that a reader will soon point out that something akin to a Journal of Mobbing Studies which I will have overlooked). Malawi, where I lived for some, seemed particularly afflicted with mob violence centred around automobile accidents, where the drivers of cars found to be at fault were often assaulted, and sometimes killed. This happened with enough frequency to create a culture of “fleeing the scene,” where drivers who were not even directly connected to an accident drove off for fear of being blamed and attacked (this was the basis for a film I shot whilst living there). I began thinking about the issue again when, recently, one of the respondents in a survey I’m helping run in Dar es Salaam was killed by a mob after (purportedly) murdering another resident. 

What leads to mobbing and why does it appear to be more prevalent in societies with dysfunctional institutions? Let’s take the armchair economist position for a moment: it would probably be fairly easy to write down a herding model where people update their beliefs about a person’s guilt based on the behaviour of others. Person 1 decides, for whatever reason, that the accused is guilty, person 2 updates his/her beliefs based on person 1′s belief, and so on, until you have a mob which is convinced that the accused is guilty. If you combine that with a utility function that inversely weights the disutility or ‘guilt’ one might feel  from being personally responsible for a death (I take comfort in knowing I probably didn’t throw the fatal stone), it’s easy to see how mobs might easily form in a context where punishment would otherwise be uncertain.

While this sort of explanation is rather intuitive, I find it a bit unsatisfying for three reasons: i) it ignores the drivers of the probability of punishment in the counterfactual and ii) it assumes that mob behaviour is solely defined over the desire to inflict justice on the guilty. It also tells us nothing about why people are more likely to be stoned to death in Dar es Salaam than, say, Myrtle Beach. A couple of thoughts:

i) What happens if we don’t stone people to death? Most socio-cultural explanations share a similar premise: people rely on mob violence precisely because they do not trust the formal justice system to get the verdict right. If the police and judiciary are capable of finding and punishing the right person, our need to rely on selection-via-herding decreases. If this is true, then strengthening the formal justice system should reduce mob violence. This falls apart if people can selectively engage the formal system – if mob justice isn’t just about guaranteeing some form of punishment, then perpetrators may still choose vigilantism over bringing in the police. This brings me to the next thought:

ii) Is this really about punishment? As with most social/political/economics concepts, Monty Python got there first: in Life of Bryan overzealous women disguise themselves with fake beards so they can throw stones at people for the fun of it. If mobs are primarily made up of young angry men, then we might begin to suspect this has more to do with the tendency for young, angry men to enjoy a bit of the ultra-violence.

Is there a quick fix here, other than waiting for the legal system to become strong enough to both reasonably guarantee punishment of those that commit the initial crime and those who engage in mob justice? Given the snowballing nature of mob violence, moving quickly to both disrupt the initial signal (that the accused must be guilty) and raise the cost of participation (a less extreme version of the Desmond Tutu method of mob justice defusal, perhaps). Do we need a roving band of mob-busters to save the day?

Or perhaps it is reasonable that mob justice is so infrequently subject to policy discussion – it is something which probably declines as countries get richer and their institutions grow more robust, so is it really deserving of too much scrutiny? 

Math fail

jumpstreet

Until  my early 20s, I never knew that one could become good at math. In high school, I ended up failing 10th-grade math.

That’s Marc Bellemare discussing his struggles with learning mathematics in high school and undergrad. For those of you don’t know, Marc is now an economics professor and is comfortable enough with math to write theory-heavy journal articles. His story about grappling with the subject and eventually learning to master it is well worth a read, especially for those who believe they are inherently bad a math.

I didn’t struggle with mathematics for quite as long as Marc did, but was nearly dissuaded at a much earlier age by the tyranny of early math education: arithmetic.

I’ve never been particularly good at adding, subtracting, multiplying or dividing. How much should we leave for a tip? I’ll let my calculator decide. It’s no surprise then that I found math in elementary school so daunting: we were required to do randomised times tables,where we had to answer as many addition/multiplication questions as possible before an alarm clock went off. I found this immensely stressful and found it very difficult to remember what 7 x 13 was when I knew that any minute now a clock was going to go BZZZZZZZ (I sense there has been a generational improvement though: my father noted that his math classes at a Roman Catholic seminary involved the lecturer smacking students in the back of the head until they got the question right).

When I go back and look through my elementary report cards, I can see how poorly I did: Cs and Ds in basic math, with worried remarks by teachers. Clearly math wasn’t my thing.

Then I was introduced to algebra. You see, arithmetic was usually taught as an exercise lesson: you don’t think about what 7 x 13 means, you remember it. But once math becomes more abstract, it becomes more conceptual and substantially less about memory. I loved algebra. In fact, I loved algebra, trig, and calculus so much that I went on to major in math in university, where I eventually semi-defected to the economics department.

Readers of this blog will probably be past the point where they make significant choices about their math education, but something to keep in mind when you have kids: it’s incredibly easy to be discouraged by math, especially in the early days when it is more about memorization. Others struggle with the more abstract stuff, but as Marc points out, this is a better reason to double down, rather than abandon it for good.*

 

*Obviously this should only be done to a point – everyone has comparative advantages.

Immigration smimmigration

"If you choose the red pill, then I'll show you just how deep the rabbit hole goes. But then we're going to stop releasing people from the Matrix. We're worried about wage effects in Zion."

“If you choose the red pill, then I’ll show you just how deep the rabbit hole goes. But then we’re going to stop releasing people from the Matrix. We’re worried about wage effects in Zion.”

Paul Collier writes about immigration for Bloomberg. I’m sure we’re only a matter of minutes away from some very serious commentary from the folks at CGD or from Roving Bandit, but here are a few of my own thoughts.

Firstly, Collier argues that new immigration inevitably will hurt the status of the recently-migrated, even if it does not hurt the native population:

The answer is that those who have already migrated lose, at least in economic terms, through the subsequent migration of others. Migrants lose because they compete with one another.

Migrants aren’t in close competition with indigenous workers. The advantage the indigenous have may be that they have better command of the language or that their greater tacit knowledge of social conventions makes them more productive.

The effects of immigration on the wages of indigenous workers vary between very small losses and modest gains. If immigration policy were to be set by its effects upon wages, the only interest group to campaign for tighter restrictions should be immigrants.

The individual behavior of immigrants evidently belies this interest: Immigrants typically devote considerable effort to trying to get visas for their relatives. But these two interests aren’t inconsistent.

An immigrant who enables a relative to join her receives benefits such as companionship. The increased competition in the job market generated by the extra migrant is suffered by other immigrants. In effect, a tightening of immigration restrictions would be a public good for the existing immigrant community as a whole.

So immigration doesn’t hurt the`indigenous’ population, but will hurt new migrants? Solution: every country in the world allows just one immigrant in its borders, then closes them forever. Seriously, it is unclear here what Collier’s assumed social welfare function is.* It’s perfectly understandable why immigration restrictions might be endogenous to levels of migration, but I’m struggling to recall any high-profile cases of recent-migrants calling for a curb on future migration.**

If we cared about general welfare and not just that of recent migrants, loosening restrictions are a bit of a no-brainer. Yes, it might depress wages in the short run for other migrants (evidence?) but compared against the enormous welfare benefits from the migration itself, this is really a second-order concern (a bit like arguing that we shouldn’t let anyone else into the life-boat because, damn it, it will be less comfortable).

Next, Collier argues that new immigration creates another set of externalities on existing migrants: more hate

There may be further social reasons that the existing stock of immigrants has an interest in tighter restrictions. The size of the immigrant stock also affects attitudes of the indigenous population. Contrary to the hope that exposure increases tolerance, the opposite appears to happen.

Heightened intolerance is a public bad suffered by immigrants as a whole, and is thus inadvertently generated by the individually maximizing migration decisions of each successive migrant. Hence, the paradox of migration. Individual migrants succeed in capturing the huge productivity gains from migration. But migrants collectively have an interest in precisely what individually is most detrimental: entry barriers.

Haters gonna hate – and haters gonna hate even more when there are more immigrants around, apparently. Again, no evidence is given to support this case. While I do think there is a worthwhile conversation to be had about how immigrants integrate into societies and how best to maintain social cohesion, falling back on the “We, the indigenous, are inherently racist, and are just going to get more racist as more foreigners show up and there’s nothing to be done about it” argument seems a bit silly.

Finally, Collier argues that migrants might not actually be that much happier and that, combined with the psychological cost of being in a new culture, immigration might be a bad deal. He turns to evidence from several studies showing happiness doesn’t increase when people are allowed to migrate.

This seems to me to be a better argument against using happiness as a welfare indicator, rather than against migration itself. It also leaves us with an entirely unsatisfactory explanation for current migration: that people are deluded about the benefits and would have preferred never to have traveled in the first place. This is particularly hard to swallow in an era where information is particularly cheap – it is relatively easy to send information back to one’s friends and family to clarify that, actually, it isn’t as cool here as I thought it was going to be.

In general, these feel like highly theoretical, armchair rationales for limiting migration. Surely we’ve moved past this by now?

 

*Update #1: To clarify, I mean the SWF Collier is using to make his case, not necessarily his personal preferences over migration!

**Update #2: a friend noted (via e-mail) that this is historically quite common – waves of immigrants turn around and try to stop the next group from landing. While I’d conceded that former-immigrants tend to resist those coming from a different national/ethnic origin, are there any cases where immigrants tried to close the door on immigration from their own country of origin?

On the ethicical approval of RCTs

From Nicolas A. Christakis:

Incidentally, another thing that’s fascinating to me is that, there’s a very funny saying when it comes to the ethical review of science, or an anecdote, which is that if a doctor wakes up in the morning and decides that, for the next 100 patients with cancer that he or she sees that have this condition, he’s going to treat them all with this new drug because he thinks that drug works, he can do that. He doesn’t need to get anyone’s permission. He can use any drug “off-label” he wants when, in his judgment, it is helpful to the patient. He’ll talk to the patient. He needs to get the patient’s consent. He can’t administer the drug without the patient knowing. But, he can say to the patient, “I recommend that you do this,” and he can make this recommendation to every one of the next 100 patients he sees.

If, on the other hand, the doctor is more humble, and more judicious, and says “you know, I’m not sure that this drug works, I’m going to only give it to half of the next 100 patients I see,” then he needs to get IRB approval, because that’s research. So even though he’s giving it to fewer patients, now there’s more review.

It would be interesting to think of the off-label analogues in development. You could argue that a lot of new government policy is essentially off-label.

Hat tip to Marginal Revolutio

In which Malawi gives Madonna a spinning roundhouse kick

norris_malawi

So Malawi was graced by another visit from Madonna recently. Somewhat miffed that she hadn’t received an invitation to go meet with President Joyce Banda, she wrote an overly-personal message to Banda (“Dear Joyce”) to ask if they could meet. To slightly complicate things further, the head representative of Madonna’s charity went after the President’s sister (who used to work for the Raising Malawi) and complained that the Material Girl wasn’t getting the right treatment from the government:

Madonna can continue her work here [even] if the politicians don’t want to welcome her because her work is all about the children who are here. The politicians can stay. Even donors are also surprised that government is treating Madonna like this when she is the biggest private donor in the country

In response, the Malawian government released an 11-point passive-aggressive smackdown. You can read the whole thing here, but one particular point stood out as being awesome and seriously bad ass:

7. If the argument is that because she is an internationally renowned star, and, therefore, Madonna believes she deserved to be treated differently from other visiting foreigners, it is worth making her aware that Malawi has hosted many international stars, including Chuck Norris, Bono, David James, Rio Ferdinand and Gary Neville who have never demanded state attention or decorum despite their equally dazzling stature. [Emphasis added]

Boom.

Hat tip to Kim Yi Dionne at haba na haba, who has covered both Madonna’s PR gaffs and the government response.

norris_poverty

 

On causality and the returns to late marriage

Miss Havisham's vast wealth is undoubtedly due to her failure to marry.

Miss Havisham’s vast wealth is undoubtedly due to her failure to marry.

Over the last week or two there has been a fair bit of chatter about a report released by the University of Virgina’s National Marriage Project. While the results pertain primarily to marriage outcomes in the United States, the general interpretation of those results is a textbook case of making strongly-causal statements using methods which are insufficient for making these claims. These two graphs, documenting the earnings of women and men by age of marriage, provide a starting point for the discussion:

knotyet_income

knotyet_incomemen

 

These descriptive stats paint a pretty clear picture, allowing us to make the following statements:

  • On average, women who have married at a later age also tend to have higher incomes. 
  • On average, men who have married at a later age mostly have lower incomes (there is a bit of an inverse relationship here, especially at higher levels of education)

These statements are not causal: I can easily say “women who have higher incomes tend to marry at a later age,” which is an equivalent point to the one above. It is just a descriptive statement. Contrast these statements with quotes from these articles on the study, including one from the chief author, Brad Wilcox:

These highly educated adults have embraced a “capstone” model of marriage that typically leads them to put off marriage until they have had a chance to establish themselves professionally, personally, and relationship-wise. This capstone model is paying big dividends to the college-educated: Their divorce rate is low, and their income is high. We find, for instance, that college-educated women who postpone marriage to their 30s earn about $10,000 more than their college-educated sisters who marry in their mid-20s

From Ross Douthat in the New York Times:

Upper-class women reap a large wage premium from delaying marriage — a college-educated woman who marries in her 30s earns over $15,000 more annually than a woman who marries in her early 20s, and when you look at household income, the premium for marrying later rises to more than $20,000. Women without 4-year degrees also enjoy a wage premium when they delay marriage, albeit a smaller one (and a very small one when you look at household income). Men, meanwhile, reap a wage premium from marrying earlier, so late marriage tends to hurt their economic prospects.

From Eleanor Barkhorn in the Atlantic:

Financially, college-educated women benefit the most from marrying later. Women who marry later make more money per year than women who marry young.

Using the above data as a basis for their arguments, all of these authors, are, to varying degrees, are making implicit or explicit causal statements: delaying marriage is good for women and bad for men. Yet, given that the Wilcox et al. study is strictly observational, with (as far as I can tell) little effort being made to discern a causal relationship between age of marriage and labour market outcomes, we’re really far more limited in what we can say. Take, for instance, a model of the marriage `market’ where women want to be picky and marry late and high income acts a bargaining chip in the matching process. Richer men will inevitably be able to secure a bride at a much earlier age and richer women will inevitably be able to stave off marriage and find a good husband at a later age. Suddenly, it’s income affecting the age of marriage, not the other way around.

I am not claiming that this model represents “the truth” and that the prevailing explanation doesn’t – far from it, but we can come up with a million different explanations for the correlation observed above which do not involve a direct causal relationship between delaying marriage and income. In general, be cautious when you’re presented with simple stories based on descriptive statistics, both in work like this as well as development research.

On MPIs and MDGs

Conan, what is best in life? "It is 1/3 crushing your enemies, 1/3 seeing them driven before you, and 1/3 hearing the lamentation of their women."

Conan, what is best in life? “It is 1/3 crushing your enemies, 1/3 seeing them driven before you, and 1/3 hearing the lamentation of their women.”

Sabine Alkire and Andy Sumner have released a short paper suggesting that the Multidimensional Poverty Index (MPI) be used as a `headline indicator’ for the post-2015 Millennium Development Goals (MDGs). If you’re unfamiliar with the MPI, you can read up on it here. Alkire and Sumner are suggesting that whatever indicators emerge out of the inevitable post-2015 intellectual bloodbath be aggregated into a single index using the same method that is used for the current MPI. This has excited some people, including Duncan Green, who thinks it will be useful in inducing governments to take the post-2015 goals seriously:

That in turn would allow the post2015 process to generate more traction on national governments (the lack of which is the subject of my paper) through league tables. Imagine if every year, all countries (including the rich ones) are ranked on a comprehensive human development table that (unlike the Human Development Index and other similar efforts) has buy in and recognition from across the international community. Each annual report would pick out the countries that have risen/fallen relative to the others. Regional tables could compare India and Bangladesh, or Peru and Bolivia, to generate extra public interest and pressure on decision makers.

I’ll go out and say it: I think this is a really bad idea. It combines the two things that make  two things that make me uncomfortable about both the MPI and the MDGs – arbitrary weights on different indicators/goals and an inflexibility to local preferences.

I’ll use a very basic example: let’s say that the next set of MDGs focuses on two things: hunger and access to clean water. After what will bound to be a seriously convoluted process, someone will agree on internationally-agreed weights on these two things. Let’s say the weights are fifty-fifty, that the final index puts just as much weight on a person who is hungry as one who does not have access to clean water.

Now consider a fictional country, Bigmacistan, which has a culture that sees hunger as being the ultimate state of poverty, much more than clean water. If Bigmacistan were allowed to assign its own weights, it would prefer 3/4 of the total weight to go to hunger and 1/4 to clean water. In fact, given limited resources, Bigmacistan will choose to combat poverty in a way that is not only seen as sub-optimal by the post-MDG framework, but would result in a fall in its global rankings, even if every single person in Bigmacistan is in agreement with its national emphasis on hunger. So differences in MPI 2.0 rankings not only reflect aggregate differences in each country’s success in fighting poverty, but differences in the structure of national social welfare functions.

What one could do is let countries set their own weights (I’ve argued that this is the only way the MPI could even be useful for governments in the long run), but this would never appease the technocrats, because once weights start varying across countries, country rankings start making even less sense.

One could argue that, if there are some indicators that we can reach a reasonably broad consensus on, then imposing these preferences on other countries might be defensible. Unfortunately, this still doesn’t adequately justify the use of the MPI, especially if they are used for annual rankings. Imagine the Bigmacistan actually cares as much about clean water as it does about hunger, but realises that, given its own complex context, it needs to deal with its hunger problem before it will have the capacity to deal with its water access problem. It draws up a national plan which ends hunger by 2020 and then improves access to water by 2025. Yet, from 2015 onwards, Bigmacistan is hounded by donors, NGOs and the media for its poor performance on the MPI 2.0 due to its lack of concern for those living without water.

Finally, any time we want to say anything interesting about the MPI 2.0, we’ll still have to unpack it into its composite indicators, a point Claire Melamed makes on Duncan’s blog:

Say the MPI 2.0, or whatever you called it, went up, or down, in a given country. You’d need an extra layer of data analysis – always fatal as that’s the point you lose people’s attention – to know why. It could be that health outcomes got a lot better, but education outcomes got a bit worse, and so the overall MPI score went up a bit. This would neither be helpful for policy makers, nor tell you much about what people think is important, and it would all be much too complicated to generate any campaigning or political energy anyway.

I do think MPI has its uses, but could we please avoid creating another worldwide indicator that doesn’t tell us very much and imposes what will ultimately be imposing fairly arbitrary weights on individual countries?

Angry post about empirical methods and philosophical plumbing

hendel_thewire_post

“We wish to announce we will no longer be reporting annual murder rates, because they represent a world view in which there is only one conceptualisation of “murder.” Murder is actually a fairly complicated, complex process, and to simply “count” these murders only stands to hide the philosophical basis for considering a crime a murder and ignores theories of change as to how or why murders happen. Anyway, the stats are all juked anyway.”

Perhaps this is nitpicking, but there was brief moment while reading Rosalind Eyben and Chris Roche’s rebuttal post on evidence in policymaking (part of a must-read exchange with Chris Whitty and Stefan Dercon), that nearly resulted in an early-morning brain aneurysm:

Let’s start by insisting that a criterion for rigorous research is that it should be explicit about its assumptions or world-view. We suggest that a weakness in many studies is that they usually focus solely on the methodological and procedural and render invisible their ‘philosophical plumbing’. The evidence-based approaches that Stefan and Chris advocate are imposing a certain view of the world, just as our approaches do. Their claims to the contrary foreclose any possible discussion about the different intellectual traditions in interpreting reality.  Theory invites argument and debate.

This argument is made time and time again with those who are both unfamiliar and intimidated by empirical methods. Let me be clear here: a comparison of means does very little to “impose a certain view of the world.” It is just a comparison of means. If I have run a randomised control trial on fertilizer use, I am answering the question “Did this treatment increase fertilizer on use, on average?” To argue that measurement has some sort of inherent, insidious philosophical underpinning is a dangerous and backward way to approach life. A breathalyser test uses various assumptions to measure a person’s blood alcohol level, but I can’t very well go about rejecting its validity because it doesn’t take into account the power relationship between the cop and the driver.

Can the use of rigorous empirical research be used to support theory or ideology? Of course. Are empirics often insufficient to answer really difficult questions. Of course. It is also the case that economists tend to think about problems a certain way, and this might not always be the way a problem needs to be thought about. Are sociological, anthropological and political methods often just as useful for providing evidence? Of course. Should these results often be considered carefully, keeping in mind the context and the various complexities and confounding factors? Of course. 

But measuring poverty, or infant mortality, while rife with methodological assumptions, does not rely on a certain view of the world, unless you classify “I believe some things should be measured” as a world view. So please, stop rejecting simple statistics as a “different intellectual tradition in interpreting reality” – it is really a very silly thing to say and diverts the argument from what really matters: what tools are best for promoting development, and how best can we implement these tools? Rigorous empirical methods are just another tool in the toolbox. Your view of the world will determine which of these tools you rely on the most.

I swear, I think this blog spends half its time trying to put the die-hard randomistas in their place and the other half trying to put the die-hard qualitatives in their place. I need to have a lie down.