Ceteris Non Paribus

Ceteris Non Paribus is my personal blog, formerly hosted at nonparibus.wordpress.com and now found here. This blog is a place for me to put the ideas I have, and the stuff I come across, that I’ve managed to convince myself other people would be interested in seeing. See the About page for more on the reasons why I maintain a blog and the origin of the blog’s name.

My most recent posts can be found below, and a list of my most popular posts (based on recent views) is on the right.

Ceteris Non Paribus

Things I would do if I had infinity billion dollars

I occasionally daydream about all the things I would do if I had more money to run my project, like having a car to get around instead of hoping that a minibus will be going where I want to get to sometime soon. When I’m actually lucky enough to get another grant, of course, I immediately budget it toward a bigger sample size. Having enough respondents to measure effects precisely is just much more important than, say, covering the cost of my housing instead of paying for that out of my pocket.

My suspicion is that this is a pretty common position to be in, at least for graduate students. Hence when I first learned about Computer-Assisted Personal Interviewing (CAPI) – basically programming a tablet computer to automate your survey – my reaction was “who the hell can afford that?” It’s a really neat technology: you can build in data validity checks, so people don’t put impossible values in a field, and also skip rules so that your enumerators don’t go to the wrong place on a survey. Even better, you don’t need to enter the data. The Development Impact Blog has a pair of posts up about CAPI, covering its advantages and potential drawbacks. They cite a paper that showed the quality of data is higher using CAPI than traditional paper surveys.

Even though the paper is quite long, it doesn’t seem to contain the key details you’d need in order to know whether it showed anything useful: the extent of idiot-proofing in the paper survey forms and the entry templates. When I design surveys, for example, I almost never have my enumerators hand-write in codes for a given response. Imagine a question on ethnic group, where 1 is Chewa, 2 is Nyanja, 3 is Lomwe, etc. Many surveys I’ve seen have a blank space where the enumerator has to write the code value. Following my advisor’s scheme, I have check boxes for each value. This makes it much harder to screw up, and checking the surveys is way easier – you can just eyeball it, and not look to see if the code is valid. I’d like to run a John Henry vs. the Machine-type contest where I design a survey that’s totally idiot-proof and an entry template full of validity checks, and compete with a CAPI. I might be able to win based on perfecting the question phrasing and translations – people say that changing a CAPI is pretty hard, and I edit my surveys many times because translations and phrasing matter a lot.

The main downside people emphasize about CAPI is that there’s a lot of programming involved. Aine McCarthy makes this point in a post describing the survey design process. That seems like a red herring to me: properly entering and cleaning data from paper surveys should involve very similar code, since you’ll want the same validity checks and verification of skip rules. In sharp contrast, the costs are extremely different and in fairly inflexible ways. To run a CAPI I’d need to buy the devices and the software needed to program them; I’d need a secure office to store them where they can’t be stolen; I’d need insurance and/or a scheme for making sure my enumerators don’t lose, break, or make off with them; and I’d need reliable power to charge the things out in the field or I’d need to make regular trips back to a place with power. Storage is a major issue – it would probably mean commuting from an office to the field sites every day. That would add tons of time to the surveys, either ballooning costs or cutting my sample size. So CAPI isn’t going to work for me, at least this time around. Maybe someday, when I win the lottery.

George R. R. Martin is apparently writing the dialogue for the Khmer Rouge trials

According to wronging rights, Pol Pot’s nephew is refusing to testify before the tribunal due to commands from “The Iron God”, which sounds like a deity that the Greyjoys would worship. And the official oath witnesses take is even better. An excerpt:

If I answer falsely on any issue, may all the guardian angels, forest guardians and powerful sacred spirits destroy me, may my material possessions be destroyed, and may I die a miserable and violent death.

The shady economics of Malawi's music industry

Yesterday, during a day trip to Blantyre, I went on a quest for an album by Alan Namoko, a (presumably) late musician who was prominent in Malawi during the 1970s and 1980s. Wikipedia describes him as playing blues and jazz, but his music doesn’t really sound like either to me – it reminds me more of American folk music.

Trying to get songs by this guy plunged me into the quasi-criminal depths of the market for recorded music here. It’s a place I’ve been to before – 95% of the Malawian songs I have were obtained through burned CDs and USB drives full of songs with such illuminating names as “Track 1” by “Unknown Artist”, off their hit album “Nthawi” (“time”). This would ordinarily cause me to feel at least a twinge of guilt, except that as far as I can tell there is no legitimate way to purchase any of this stuff. There are definitely plenty of dudes at markets selling music, but all of it has the feel of being made at an internet cafe down the road. I’ve seen a few more legitimate-looking CDs on sale in shops aimed at tourists (whence my Lucius Banda collection, for example), but that’s about it.

This has some interesting consequences. The first is that people don’t always know the names of even fairly popular songs. Last year it took me about a month to learn the name of that summer’s top hit, “Koka Kola” (by the Zambian group Organized Family [the “r” may be optional, or even deprecated]). I even met one person who had the song as her ringtone but didn’t know what it was called. There are a number of albums that I’d like to buy just because I like the artists and want a) more of their music and b) the actual names of these songs, and the artists themselves. But lacking the names, that’s fairly hard, and what’s on sale would probably be pirated and disorganized anyway.

Second, Malawi’s music industry has already transitioned to the place where America’s is going. All the money is in live shows. As a result, the top acts tour constantly. Last summer I missed big shows by Ma Blacks and Soldier due to fuel shortages, but due to the non-stop touring they both came back to town before I left. This is good for fans, and at least in the US it’s good for artists because they keep a bigger cut of the revenue.

Third, because touring is where all the money and action is, there is the risk of music by artists who have retired disappearing entirely. As I trotted through the wonderful madness of Blantyre’s open market asking about Namoko’s music, I got a disappointing number of blank stares. The guys (I’ve never seen a woman working at one of these semi-legal music stands) who did know who he was commonly said that no one would have his music “anywhere”. One actually did – on an old, pirated cassette tape, which he admitted was useless to pretty much everyone. I finally did get a copy of a few of Namoko’s songs, from one gentleman’s well-organized mp3 collection. When I asked what he wanted in exchange, he asked for “softwares”. I was unsure what to offer – I’m a bit out of touch with the software piracy scene – but it turned out he wanted Skype and Microsoft Security Essentials; both are freeware, available to anyone with an internet connection.

So Namoko lives on, in digital form, but I wonder for how long. I’ve only found one place, a website, that even attempts to offer his music for legitimate sale, and I think they’re stocked out. It’d be a damned shame if this country’s musical history faded into oblivion because there’s no money in it.

Why on Earth do a third of Malawi's female police officers have HIV?

Reports on high-risk groups for HIV in Malawi often give the prevalence of the virus for various subgroups considered high-risk. Some of these are obvious (sex workers, for example, have an infection rate above two thirds) while others require more introspection to understand (police officers and school teachers travel frequently and have a lot of bargaining power to demand sex in certain situations). But the story for the high prevalence among police officers is implicitly a male one: we think that cops can use their position of authority to pursue more risky sex, and stereotypically it’s a male cop who does that.

The data from Malawi tell the opposite story – it is the women on the police force, not the men, who have the higher infection rate. Part of this can be ascribed to the higher per-act transmission rate for women (for unprotected sex with an infected partner) but that is compensated slightly by the lower overall prevalence for women’s potential partners (i.e. men). So I really am at a loss to explain why 32.1% of female police officers tested positive for HIV, versus 24.5% for men. Another entry in the seemingly boundless list of mysteries related to sexual behavior and HIV here.

Deprivation and life expectancy in London: things really aren't that bad

Owen Abroad links to a map of life expectancy and deprivation (poverty, basically) in London. The spatial correlation between poor areas and places with lower life expectancy at birth is supposed to be shocking – but based on my ocular analysis of the data, we’re looking at a gap of 5-9 years between the poorest and the richest areas. Also, and more important, the poor areas still have a life expectancy at birth of 78 or more (the article identifies a low outlier at 74). 78 happens to be the average life expectancy for all Americans. And while I don’t have a spatial map like this at hand for any US cities, I’m sure that the discrepancies would be even worse.

In California, black males have an overall life expectancy of 68.6, or 7 years shorter than white males. Given the strongly ethnically segregated neighborhoods in that state, and the fact that the 68.6 average includes some wealthier blacks who live in other neighborhoods, a map of Californian neighborhoods would have a drastically lower average than the above one of London and probably a higher variance as well. If you showed me the map above and told me it was San Francisco, I would have a party to celebrate all the progress we’ve made.

Also, even after digging into the deprivation index for a while, I’m unclear why the designers didn’t just use incomes. That might leave out other factors that are important in a broader concept of poverty, but it has the advantage of being actual data and not a constructed number that privileges the preferences of whoever made it up.

Cashing in on discrimination

This past weekend I went up M3 to Liwonde National Park for a day and a half. As proof, here is me with some hippos:

I got there by hitching a ride with Brigitte Zimmerman, an awesome political science PhD student from UCSD who I met at WGAPE. Brigitte is here doing her own dissertation research, and was spending the weekend with three other female friends. Liwonde is maybe a 45-minute drive from Zomba, and we were stopped by police more times during that drive than I have ever been in all the time I’ve driven a vehicle here (several weeks).

Nothing happened at any of the stops, which to be honest are fairly routine on the roads here, but it got me thinking. An informal survey indicates that there’s a definite gender discrepancy at play here: women are stopped more often than men, and white men are stopped least of all. The traffic police here are often looking for fines; maybe they think women are more likely to just pay a dubious fine instead of arguing.

So this whole time I’ve been playing with loaded dice, and hardly realized it. This makes me wonder what other subtle benefits I’ve gotten here as a result of my race and gender. It would surprise me very little if I got better prices, at least in terms of initial offers.

Your daily dose of crazy nonsense about HIV

My current research is motivated by the fact that many people don’t realize that serodiscordance – sexual relationships where one partner is HIV-positive and the other is negative – is a possibility. The standard assumption is that transmission is very high-probability, so that discordance is rare; that assumption is false. While the misunderstanding is common worldwide, it has few practical consequences in the US, where people rarely know many folks with HIV. In Malawi, where the virus is common, though, people tend to realize that sometimes people don’t immediately contract the virus.

This has led to the promotion of a number of rumors about HIV transmission that involve certain acts being totally safe or certain people being immune. A really prominent one all over the Southern Region is that people with Type O blood are immune to HIV. Nothing could be further from the truth: ABO blood type has to do with your red blood cells, and HIV spreads through white blood cells. Moreover, the only study I know about HIV and blood type actually shows that people with type O blood are at more risk. This study is pretty badly designed, though. It doesn’t use random sampling, and blood type is correlated with other factors that impact HIV prevalence such as ethnic background. I’d venture that there’s really no relationship, but if anything there may be a small positive effect from type O blood – exactly the opposite of these rumors.

Now, the people who think this aren’t stupid – they’re operating off the information they have available, which doesn’t give them many ways of understanding serodiscordance. My understanding is that typical HIV prevention messages here are a stories about a single poor choice leading inevitably to death. If they’ve heard there are reasons why people don’t get HIV, this can help them sort out the conflict between the idea that HIV is transmitted for sure if you have unprotected sex, and the fact that some couples are discordant. So when I encounter this rumor, I always ask where people heard it. The most common place was through friends. In one case, though, a guy said he learned it in school. From whom? A local health official, there to teach them about HIV. Awesome.

As an added bonus, another man said that he had been taught in school, by a local health official, that HIV was not found in semen or vaginal fluid (and so unprotected sex is safe as long as there’s no bleeding). That is also wildly untrue.

I don't think I can explain this one

Funniest thing I’ve seen in a while – If you get it, you get it.

For some reason it reminds me of an exchange in my freshman honors electricity & magnetism course. E&M involves tons of different formulas, and we spent most of the term learning how to apply them and where they come from. These are hard, and one of the best things about majoring in physics is that almost every exam was open-book, open-notes – the tests were about your ability to solve problems and understand the material, not about memorization. On the last class before the first midterm exam, there was a review of the material, and the floor was opened for questions.

Student: “Will we get a formula sheet on the exam?” (to aid with remembering all the formulas)

Professor Leonard Susskind: “No…” [pauses, strokes his beard] “…you are allowed to re-derive the formulas during the exam.”

Marking one year since the July 20th protests

Today marked one year since the violent protests that rocked Malawi on July 20th, 2011. dadakim has commentary on the healing process, as well as on the fresh unrest over the removal of vendors in Lilongwe. She also links to her blog post from that day last year, which was one of the best sources at the time for learning what was going on. I still get chills reading it. For context, I had literally just left the country after my project last summer – I think I flew out on the 18th, and the first protests were on the 19th. There had been protests all summer, and I had even watched a few up close and followed them through town here in Zomba. Then, just after I left, everything exploded into violence. I was caught totally by surprise, and it felt completely surreal. Of all the low points of Mutharika’s administation, it was probably the worst, surpassed only by the near constitutional crisis that followed his death.

Today, I didn’t even realize that this was the anniversary until I saw it in the paper – in an insert, not on the front page. A sign of the drastic change here since April – and of progress, maybe. But 20 people died a year ago, for no defensible reason, and it seems strange to ignore that.

On pictures

This blog has substantially fewer pictures than you get on your typical white-person-in-a-tropical-country type blog. Part of that is its nature – those are often one-shot affairs partly designed as a place to put pictures, whereas this is intended as a permanent place for my rantings and link-sharing, now that sharing on Google Reader is gone. Another part is that I’ve done this before; this isn’t even my first trip to Malawi, let alone outside the country.

But the big reason is that I’m not sure how cool I am with certain kinds of picture. Scenery is nice, no doubt, as are funny signs and the like. Here’s a picture of the place where I was testing out data collection instruments yesterday:

I love my job

The best kind of picture, though, has people in it: fun pictures of you with friends, or, ideally if you’re a college student spending three weeks of your summer saving the world, a shot of you surrounded by a mob of happy African children. I’ve got some of the former, and even a few of the latter (in some places I’ve been, all the local kids have surrounded me yelling “Jambule!” – “Take a picture!”), but I’m not putting them here.

The reason is a matter of consent, and power dynamics. It’s hard to imagine a scenario where I take a picture of a Malawian and they have truly consented to having their face posted on the internet for everyone to see (let alone turned into an internet meme). Think about the kids, from villages out in Zomba District – have they heard of the internet? Do they know what it is? Or if I’m taking a picture of a Malawian friend, are they thinking there’s potential monetary gain it for them, or, if they’re an employee, that they have to consent because I’m their boss?

And that’s if even I try to ask – I think standard practice is just to take pictures and use them. This is generally legal, and I don’t object to it on principle, but it doesn’t sit totally right with me. Even in cases where I do think that people are okay with me sharing pictures, Facebook is probably a more appropriate forum; at least there are basic privacy controls there. This blog probably won’t get have too many photos of people on it unless I’m in a situation where I think the playing field is decently even between me and the other person, or tilted in their favor.