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.

Is the land grab debate a proxy war?

unicron

Is the land grab debate about property rights or consolidation?

So much to write, but so little time to do so. Instead I’d just like to end the week with a quick thought on the evolution of the land grabs debate. I’ve been slowly picking my way through Lorenzo Cotula’s fairly comprehensive book on large scale land acquisitions, an I was stuck by the following passage:

“Also, in some cases it is difficult to tell whether a reported deal relates to a new plantation, or to the acquisition of an existing plantation – for example, where a state farm is privatized. The two types of deals would have very different consequences for pressures on land, though even acquiring an existing farm can increase land competition – for instance, if an old state farm has been partly occupied by squatters who are evicted following the privatization, or if the deal involves expanding the existing plantation.”

Cotula is reflecting on the difficulties of discerning land purchases in the Land Matrix which involve some form of consolidation (land owner by multiple smallholder farmers being converted into large-scale farms) and those which do not change the scale of land ownership. This is an important distinction, as it implies entirely different concerns over large scale land acquisitions.

For a large part, the land grab debate has been presented as an issue of property rights: rural communities are having their (possibly customary) rights to land violated when governments lease or sell the land to large national or international firms. This implies direct welfare losses from losing control of a productive asset – imagine if someone showed up and stole your laptop or your main mode of transport (or your house).

But there is a second issue here: even if property rights were perfectly enforced  and all large scale land acquisitions were both fair and voluntary, they would still involve a significant amount of land consolidation, with smallholder plots being converted into much, much large farms. This raises an important question: once we sort out the rights issues, what form of agriculture would we actually like to encourage in these settings?

It is no secret that many NGOs, such as Oxfam, have a bias towards smallholder farming (let’s lead aside whether or not that bias is justified or not, it could very well be). Is the current onslaught on large scale land deals by these NGOs purely about protecting the rights of people, or is this just another front in a much larger war on land consolidation?

Not only the state will bleed

There wasn’t much for me to do when I first joined the Budget Division of Malawi’s Ministry of Finance back in 2006. My particular position had been vacant for almost a year, so it took a bit of time before the acting budget director grew accustomed enough to start diverting work my way. One of the very first things I worked on was an attempt to reconcile the difference between expenditure ceilings set by my department and actual reports of expenditure from the Accountant General’s department.

What complicated this process was the fact that the Accountant General had recently adopted an Integrated Financial Management System (IFMIS), essentially a comprehensive software platform for approving and tracking expenditure. A lot of promises came with IFMIS – the ability to track expenditure in real time and keep a tight leash on expenditure by line ministries. Yet, when I had arrived, the budget department had yet to fully adopt the platform, meaning that our (often fairly specific) budget ceilings had to be manually reconciled with IFMIS-generated expenditure reports.

I doubt that the budget director seriously believed that this greenhorn civil servant was really going to accomplish much with this work and probably saw the task as something to keep me busy while I grew more accustomed to my environment. Even so, I quickly noticed that IFMIS-generated reports seriously deviated from what was being approved by the Budget Division, sometimes even showing expenditure which was above and beyond what had been mandated by our department.

At my director’s prompting, I visited the relevant department at the Account General’s to request more detailed reports from IFMIS. The likely culprit was some of data problem, and I was curious to get to the bottom of it, seeing the whole exercise as a problem with some sort of technical solution. While the civil servants I spoke to at the AG were friendly enough and agreed to send me reports, upon my return to the Ministry of Finance it was later made clear to me that the AG wasn’t too fond of this unknown fresh-faced mzungu making random requests. Not long after, more pressing work diverted my attention, and this particular issue faded into the background.

Later, our own department grappled with the adoption of IFMIS. While technological solutions are frequently touted as solutions to institutional problems (this platform will eliminate corruption!), my experience was that without some basic level of capacity in place, even the most advanced platform was doomed to fail. Hence, if two government ministries can’t keep their budget tallies synchronised in Excel, they are unlikely to be able to get a more complex `black box’ system to work properly.  This is problematic, because when finance systems don’t work properly, it’s very difficult to tell the difference between corruption and incompetence.* My feeling at the time that the discrepancies between the AG’s expenditure records were due to the latter, even though I heard the occasional, unsubstantiated whisper that someone at the AG was stealing money.

This was surprising to me, as there had been a fairly visible crack down on corruption and leakage during the first term of then-president Bingu wa Mutharika. However, it was widely recognized that during his second, more tumultuous term (which began after I had left the country), government systems became more porous and corruption become more common.

One might have expected things to improve upon Mutharika’s sudden death and the ascension of the pragmatic Joyce Banda to the presidency. Yet despite wowing a lot of donors and even some skeptics – including yours truly – her government seems to have inherited many of its predecessors failings: a recent scandal has broken out over implications that there has been substantial theft by employees of the Accountant General’s department, who exploited loopholes in IFMIS to siphon off money.

We tend to lump all dodgy dealings into the broad category of corruption, but there is a clear difference between institutionalised corruption, where political leaders divert resources towards their own benefit, and the kind of rampant theft which goes on when you have a leader who either is unaware of or cannot control corrupt practices. Banda’s situation clearly falls in the latter – given that she has, until very recently, ruled over cabinet  of former members of Mutharika’s party as well as the opposition – she has always been in a precarious position and thus unable to fully keep everyone in her government in line.

The scandal hasn’t been completely bloodless. The recently-appointed director of the Budget Division, Paul Mphwiyo, was nearly shot to death following his attempts to close the loopholes leading to theft of public resources. I knew Paul during my time in Malawi: he was serving as an assistant budget director when I was working for the Ministry of Finance, although we didn’t often work closely together. Let’s hope he recovers quickly and his assailants are eventually apprehended, although I have my doubts about the latter.

For those wanting to keep tabs on the scandal, Kim Yi Dionne remains an excellent source for recent Malawi news and analysis.

 

*This confusion can be easily exploited.

Update: This post got a little more attention than I thought it would, so just wanted to add a little addendum.

I want to be cautious about drawing too many conclusions from my (very brief) interaction with the AG’s system – the Cashgate scandal is another animal entirely. In weighing the corruption or incompetence possibilities, it’s highly likely that my situation fell in the latter. I just felt it was worth noting that these things aren’t always clear, and that there was a bit of an administrative wall between the Account General’s Office and the Budget Division of the Ministry of Finance (they were, at least when I was there, separate `votes’ on the cabinet and in separate buildings.) Also, for the sake of my former department, I want to make it clear that this thing at least seems to be entirely of the AG’s making, and I saw nothing in the Budget Division during my time there that suggested any wrongdoing of this sort.

An apple a day means nothing in a complex system

"But Mulder, what I'm seeing here goes against every single case study and ethnographic paper ever written."

“But Mulder, the evidence I’m seeing here goes against every single case study and ethnographic paper I’ve ever read.”

Recently there has been much fuss made over how researchers and practitioners should be more cognisant of how development policy plays out in environments which are characterised by complexity. While many have used the presence of complex systems to motivate a move towards more experimentation, tracking and empiricism, others have argued that we should instead eschew rigorous empirical methods (such as RCTs) and one-shot policy instruments and opt towards a more dynamic, qualitative approach to development policy.

As of late I have been particularly wary of this second camp, especially when the argument that data-driven methods and randomised controlled trials have little place in a world of complexity. Let me explain why this makes me uneasy.

The human body is itself a complex system, characterised by feedback loops and a lot of unknown parameters. Despite the fact that we know a surprising amount about what makes us tick, thanks to both theory and evidence from biology and medical science, we’re surprising inept at determining long term outcomes. Even so, when my complex system throws up signs that things are not well, I go to see my doctor. After examining me and assessing my symptoms, sometimes through laboratory testing, he makes a diagnosis. Based on that diagnosis, he chooses a treatment, often by selecting a pre-approved medication which has been tested using an RCT.

Let’s think about this for a moment. Most medical research is able to cleanly discern short-term benefits to taking a certain medication. While these medicines are developed using a heavy dose of (biological) theory and iterative testing, trials are rarely long enough to determine what the long term benefits or side-effects will be. While researchers can use previous results and theory to determine that chemical X will result in reaction Y in a human body, they rarely can account for all the possible effects. Randomised controlled trials get us part of the way there, but frequently cannot account for long term effects. So, while we can measure the aggregate effect of a treatment on an incredibly complex system on the short run, we really can’t say that much in the long term, nor can we say much about how these treatments might interact with other treatments.

In fact, it is with predictions about health over the long term where the precision of experimentation often gives way to less robust evidence (such as extended observational studies) or more ad hoc forms of rationalization (is milk good or bad for you?). Similarly, many of the bigger questions in development (how do we improve institutions? What causes economic growth?) are more difficult to address using the most rigorous methods. It is in these areas that, quite naturally, the randomistas have been least successful in their domination of the policy debate.

While we should find all of this disconcerting, the (current) inability of medical RCTs to give us definitive answers on what makes us live longer or be healthier in aggregate is hardly a reason we should rely on them any less. Imagine a world in which your doctor didn’t have access to any randomised medical research. Health professionals would have to resort to casual Bayesian inference to treat people (did John die when I gave him chemical Z?), and would have little sense of which medicines were `proven’ to work. We tend to look down on off-label use of medication, but in a world where rigorous scientific testing isn’t the norm, all prescriptions become off-label. It is a world not a million miles away from the one portrayed in the Mitchell & Web sketch “Homoeopathy A&E.”

The sketch also highlights what the development policy world is like when we toss out rigorous empirical evidence. Yes decisions are made based on qualitative expertise, but they are made without either definitive evidence (did this make a difference?) or appropriate empirical feed back (are things getting better?). A healthy dose of qualitative work is essential in development policy-making, but a world in which all decisions are done qualitatively is  far from ideal: how many of you would wish to be treated by that doctor who had been practising for 40 years, but had never read (or believed) a single medical study?

Just as medicines shown to work using rigorous clinical trials are an essential tool for a doctor navigating the complexities of human health, policies which have been shown to work in some context with an RCT become one of many tools policy-makers can use when operating within a complex policy environment. These types of rigorous trials certainly won’t solve all of our problems, but they are still extremely, extremely useful, even in a complex system. I’m glad that someone is putting out useful albeit marginal medicines which make me feel better when I get sick. It would be even better if someone could figure out more comprehensive interventions which take into account my entire biology, but in the meantime I’ll take what I can get.

The unbearable lightness of being a dead salmon

Oh my god, how many salmon died by my hands during my Odell Lake sessions?

Oh my god, how many salmon died by my hands during my Odell Lake sessions?

The neuroscientist Gregory Burns describes how he used functional MRI scans to show that dogs have similar basic emotional reactions to humans roughly equivalent to a level of sentience of a human child:

In dogs, we found that activity in the caudate increased in response to hand signals indicating food. The caudate also activated to the smells of familiar humans. And in preliminary tests, it activated to the return of an owner who had momentarily stepped out of view. Do these findings prove that dogs love us? Not quite. But many of the same things that activate the human caudate, which are associated with positive emotions, also activate the dog caudate. Neuroscientists call this a functional homology, and it may be an indication of canine emotions.

The ability to experience positive emotions, like love and attachment, would mean that dogs have a level of sentience comparable to that of a human child. And this ability suggests a rethinking of how we treat dogs.

Interesting. I’m not so sure that sentience is a necessary prerequisite for the humane treatment of animals, but it certainly would add weight to them oral argument.

Except I’m not so sure I believe the result. So I had a quick look at the study and it appears this entire result is based off of just two dogs, and the statistically significant increase in caudate activity appears to be restricted to a specific point in time after the test (so while the caudate activity seems to be significant X seconds after, it doesn’t appear to be significant X-1 or X+1 seconds after, which does raise some suspicions that the researchers cherry-picked the results ). The presence of similar activity in two dogs does bolster the result somewhat…. but come on, two dogs?

This might be a good time to bring up the famous dead salmon study again. fMRI studies are known for being particularly dodgy on the statistical inference front. A few years ago a group of Dartmouth scientists highlighted this point when they put a dead Atlantic salmon in a fMRI, showed it pictures of humans, and managed to get a statistically significant emotional response.

You see, fMRI is apparently a particular noisy way of measuring brain activity, so it’s fairly easy to throw up false positives, especially given the unit of analysis is essentially a voxel. The Dartmouth study revealed what happens when you don’t make simple corrections to account for this. Now, Burn’s study did make these corrections, so we can’t quite claim that dead salmon have a similar level of sentience to dogs. Still, we should be somewhat sceptical of an fMRI result until it is replicated again.

When every argument begins with “is it better than cash?”

"Where the hell is the Jaeger?" "Oh the government couldn't figure out how to evaluate the anti-Kaiju programme, so they just do cash transfers now."

“Where the hell is the Jaeger?” “Oh the government couldn’t really figure out how to evaluate the giant robots-fight off giant aliens programme, so they basically just do cash transfers now.”

Kevin Grier grumbles about the IDA, arguing that its investments couldn’t possibly stack up to cash transfers:

The last 3 year replenishment of IDA was for 49.3 billion dollars. So for a decade of IDA, we can use 150 billion dollars as a cost number. People, for $150 billion dollars, you could give 75 million people each $2000 in cold hard cash. From my point of view, that sounds a lot better than giving them “access” to services. Now sure, there are aid agencies worse than the IDA (phone call for USAID), but there is nothing in Mombrial’s post that backs up his claim that the IDA is a good investment, and in my opinion, it’s actually a bad investment relative to unconditional cash transfers.

Even without the growing body of empirical evidence indicating that just giving cash is an incredibly cost-effective way to increase welfare, there is an extremely compelling theoretical case to be made for cash transfers. Poor households have preferences (replace these with `needs’ if you are so inclined, although there are important distinctions between the two), and no one will ever have better information on these preferences than these households. Transferring households cash allows them to best allocate these new resources to meet these preferences – otherwise, we run the risk of wasting resources on stuff that households just don’t want.* Combine this with the fact that cash transfers are getting quite easy to make, especially in the era of mobile money, and they appear to be a reasonable standard by which to compare all other interventions.

Yet, the most ardent supporters of cash transfer programmes often forget that many societies (read: all societies) are still struggling with pretty severe collective action problems which inhibit the provision of public goods. It’s far from clear that distributing cash will solve these problems: if a village of people haven’t banded together and produced a well-functioning school by now, although giving them cash certainly increases their purchasing power to do so, it’s unlikely to solve the basic collective action problem resulting in the failure to produce the school.

This is important, as there are a range of public goods (or semi-private goods which have substantial externalities) which we can imagine might increase welfare a great deal more than a cash transfer of equivalent cost: schools, health facilities, roads, a functioning police force. Basically, any semblance of a local or national state. How many of you would vote for your own government to transfer its entire budget evenly across the population and then shut down all its operation for good? It certainly would make it easier to pay the rent next month, if your apartment complex hadn’t been burned down by the marauding hordes yet.

Now, if the collective actions problems we care about have already been solved by the market, we should be less worried. Despite a steady flow of misinformed rhetoric from NGOs suggesting that private schools in developing countries are a distraction, there is a great deal of evidence suggesting that in settings where the state is failing to provide quality schooling, private schools present a reasonable (and probably strictly superior) alternative for poor families. In these settings, unconditional cash transfers should be enough. However, there are going to be a lot of contexts where markets are not filling these gaps. For example, rural health clinics tend to be the preserve of government or NGO work, rather than the private health sector, so the effect of income on health outcomes in these contexts is going to be more complex.

The hypothesis “is intervention X better than cash?” is relatively easy to test for a whole slew of interventions: run an RCT and see if this is the case. Yet, while development economists are getting quite good at making and replicating these comparisons for private or small-scale interventions, many of the large public-good investments that have the potential for a large payoff remain difficult to convincingly empirically evaluate (I am somewhat optimistic that we will get there, but we’re certainly not there yet). The current bias towards cash represents not only a positive assessment of the returns to these types of interventions, but also a preference for interventions that can easily be shown to work.

Yet we know that public goods matter and that cash-transfers, to the extent that they cannot be taxed by the state, are unlikely to help in this regard. Multilateral lending/aid organisations like the IDA tend to focus more on projects which have some public good element, such as infrastructure. Whether or not these organisations are any good at producing successful, cost-effective projects is certainly a question we should be asking. But the choice that Grier presents us with is a false one: that we must choose between wasteful public good spending and cash, as if the cash-only equilibrium is the only one that could ever make any sense.

I am frequently guilty of wheeling out the “but is it better than cash?” argument whenever I see an intervention which looks wasteful or too paternalistic** for my taste, but we should be cautious not to use cash transfers as the appropriate gold standard for every intervention. There are plenty of public-good-type interventions which are (currently) hard-to-measure but important. Whether or not aid donors and governments are any good at funding these interventions should be the starting point for the discussion.

*I’m ignoring a lot of potential problems here by using households instead of people, as well as ignoring issues with time-inconsistency, etc, because I want to focus on one particular argument in this post.

**There are those that doubt the efficacy of unconditional cash transfers due to concerns over the ability of households to discern what they should be spending the money on. These concerns are not entirely unfounded – we are all subject to a variety of cognitive biases which can lead to suboptimal decisions. I choose to ignore these concerns here, not because I don’t think that they apply, but because I’m pretty skeptical that aid agencies and charities would be better at determining optimal private expenditure patterns than households.

Of tribes and titles

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“Sol, we’re new here and don’t really know anybody, so get over to Swearengen and secure us a title deed to some property.”

Things have been a bit quiet recently – part of this is due to a lengthy field-based ethnographic research trip focused on the interaction between late 80s and early 90s UK dance music and Croatian culture. I also was tied up by the always-impressive `Growth Week‘ held by the International Growth Centre Growth at LSE. I’ll let you guess which was more fun.

So let’s start with some blatant self promotion – I’ve got a new working paper out. Here’s the short, short version: most unplanned settlements or `slums’  in most of SSA are dominated by informal tenure, where your right over land is more likely to be determined by customary law, social connections, or ad hoc semi-formal methods of establishing occupancy, than it is by a formal land title. Some households are going to have an easier time of securing their tenure through informal means, others who face higher costs to doing so might be more likely to accept property rights provided by the state. I examine this by looking to see whether or not households in Dar es Salaam which are ethnically-isolated (surrounded by neighbours from other tribes) are more likely to buy property rights offered by the Tanzanian government.

For more detail, head over to the CSAE blog, where I talk about the paper in a little more detail.

I’ll leave you with an image which sums up all the fears and uncertainties of tenure in slums: a landowner on Oxford Street, Accra, who desperately wants to avoid the sale of his/her property (thanks to Elwyn Davies for this photo):

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The property ladder here and there

Once plentiful, land has become scarce, and competition fierce. The district population has been growing fast………. Youths struggle to find any land to sustain their new families. In some villages, it is difficult to get even one hectare. In the village of Amanikrom a young man eager to farm could only get a fifth of a hectare. So the landless youth work their way up by starting as labourers or sharecroppers. In the past, sharecropping attracted migrants only from other parts of the country. Today, young members of the landowning family have to resort to sharecropping too. Meanwhile, much land is in the hands of absentee landlords who work in Accra and use part of their wages to pay for agricultural labourers.

That is from Lorenzo Cotula’s recent book on land grabbing in Africa. For those of you who consider this to be a third world problem: read the segment above one more time, but replace “land” with “housing”, “fifth of a hectare” with “studio apartment”, “sharecropping” with “renting”, and “agricultural labourers” with “council-approved extensions.”

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