Archive for January, 2012

Overhead at WWS

Last week a classmate of mine at the Woodrow Wilson School shared this story, which I in turn share with permission.

Today G and I were doing our impossible econ problem set in Schultz Café. It was about consumer surplus so there were some nice geometric properties, and it was fun finding the areas of the triangles and trapezoids. I said out loud, “I don’t how to do it the econ way, G. I only know how to do it the 9th-grade-math way.”

Guess who was sitting right behind us?

Christopher Sims.

For background, search this article for the paragraph on Sims and the SAT. Maybe this is why economics folks might think we public policy students aren’t so great at math? Related: how to fight impostor syndrome.


01 2012

Coincidence or consequence?

Imagine there’s a pandemic flu virus on the loose, and a vaccine has just been introduced. Then come reports of dozens of cases of Guillain-Barré syndrome (GBS), a rare type of paralysis. Did the new vaccine cause it? How would you even begin to know? One first step (though certainly not the only one) is to think about the background rate of disease:

Inappropriate assessment of vaccine safety data could severely undermine the eff ectiveness of mass campaigns against pandemic H1N1 2009 influenza. Guillain-Barré syndrome is a good example to consider. Since the 1976–77 swine influenza vaccination campaign was associated with an increased number of cases of Guillain-Barré syndrome, assessment of such cases after vaccination will be a high priority. Therefore, it is important to know the background rates of this syndrome and how this rate might vary with regard to population demographics. The background rate of the syndrome in the USA is about 1–2 cases per 1 million person-months of observation. During a pandemic H1N1 vaccine campaign in the USA, 100 million individuals could be vaccinated. For a 6-week follow-up period for each dose, this corresponds to 150 million person-months of observation time during which a predicted 200 or more new cases of Guillain-Barré syndrome would occur as background coincident cases. The reporting of even a fraction of such a large number of cases as adverse events after immunisation, with attendant media coverage, would probably give rise to intense public concern, even though the occurrence of such cases was completely predictable and would have happened in the absence of a mass campaign.

That’s from a paper by Steven Black et al. in 2009, “Importance of background rates of disease in assessment of vaccine safety during mass immunisation with pandemic H1N1 infl uenza vaccines”. They also calculate background rates for spontaneous abortion, preterm delivery, and spontaneous death among other things.


01 2012

Monday Miscellany


01 2012

Coast to coast

One of my classmates drove from Los Angeles to Princeton and set up his camera to take photos along the way. He edited the results into this video:

In his words: “California to Jersey, 5,000+ photos, 2,800+ miles, 45 hours of driving, 0 speeding tickets, 1 driving hero.” And yes, they stopped to sleep (though maybe not enough).

Things to watch for include the moon, the palms trees at the beginning, the changes in lighting (including sunrise around 1:40), and how many tractor-trailers they pass. But what strikes me the most is the uniformity of the road system — the two-lane interstate highway, the road markings, the signs, the road-side stops. As outdated as our transportation system is, it’s still a phenomenal public good when you compare it to what came before. It took Lewis and Clark a lot longer and they didn’t even go as far.


01 2012

Generalized linear models resource

The lectures are over, the problem sets are submitted — all that’s left for the fall semester are finals in a couple weeks. One of the courses I’m taking is Germán Rodríguez’s “Generalized Linear Statistical Models” and it occurred to me that I should highlight the course website for blog readers.

Princeton does not have a school of public health (nor a medical school, business school, or law school, amongst other things) but it does have a program in demography and population research, and Professor Rodríguez teaches in that program.

The course website includes Stata logs, exams, datasets, and problem sets based on those data sets. The lectures have closely followed the lecture notes on the website, covering the following models: linear models (continuous data), logit models (binary data), Poisson models (count data), overdispersed count data, log-linear models (contingency tables), multinomial responses, survival analysis, and panel data, along with some appendices on likelihood and GLM theory. Enjoy.


01 2012

Infectious history

The late Joshua Lederberg, a Nobel-winning molecular biologist (at the age of 33!), wrote an essay on the history of our fight against microbes titled “Infectious History.” It’s readable and covers a lot of ground fairly succinctly, and there’s a non-paywalled version here. (The formatting isn’t great, so it’s a great excuse to install the Readability plugin if you haven’t already.) One of my favorite excerpts:

Bacteriology’s slow acceptance was partly due to the minuscule dimensions of microbes. The microscopes of the 19th and early 20th centuries could not resolve internal microbial anatomy with any detail. Only with the advent of electron microscopy in the 1930s did these structures (nucleoids, ribosomes, cell walls and membranes, flagella) become discernible. Prior to that instrumental breakthrough, most biologists had little, if anything, to do with bacteria and viruses. When they did, they viewed such organisms as mysteriously precellular. It was still an audacious leap for René Dubos to entitle his famous 1945 monograph “The Bacterial Cell.”

And on diminishing returns on extending life expectancy (at least in industrialized countries) since 1950:

Other statistics reveal that the decline in mortality ascribable to infectious disease accounted for almost all of the improvement in longevity up to 1950, when life expectancy had reached 68. The additional decade of life expectancy for babies born today took the rest of the century to gain. Further improvements now appear to be on an asymptotic trajectory: Each new gain is ever harder to come by, at least pending unpredictable breakthroughs in the biology of aging.

Read the rest. I came across Lederberg’s article in a footnote to Adel Mahmoud’s article “A global road map is needed for vaccine research, development, and deployment.”


01 2012

Monday Miscellany

  • If you’re considering grad school in international development / public policy / public health you should read these recent posts by Rachel Strohm and Karen Attiah. They write specifically about development studies, but in my limited experience the criticism can be extended to schools of public health and more broadly to policy schools as well.
  • I updated my post from October on Andrew Grove’s proposal to restyle FDA trials with a link to Derek Lowe’s round-up of critical responses, which help explain why our drug approval system – flawed though it may be – could be made much worse by such reforms.
  • Potentially useful: a list of software for monitoring and evaluation.
  • Ever wanted an infographic of the deadliest outbreaks in history? Now you have one. Of course, Steven Pinker would want to resize all of these to be relative to the world population at the time of the pandemic…
  • Brazil pharma pressure and Wikileaks at Foreign Policy.
  • Here’s a critical essay by David Rieff from a while back – “Altruists in Wonderland: UN Millennium Development Goals.”
  • Completely unrelated to anything else I’ve read lately, but still fascinating: Justinian and the Nike riots.
  • From Flowing Data: US road fatalities mapped over 9 years:


01 2012

Does grad school make you liberal?

In short, no, liberals are just more likely to select themselves into grad school attendance (PDF). The abstract:

This paper analyzes longitudinal data to evaluate three claims that are key to a recently developed theory of professorial politics. The theory explains the liberalism of the American professoriate as a function of reputation-based self-selection: because academia has a reputation for liberalism, liberals are more likely to pursue graduate degrees and academic careers. We examine whether in fact young Americans who identify as liberal are more likely to enroll in graduate programs with the intention of completing a doctorate; the proposition that such a tendency cannot be explained away by variables unrelated to occupational reputation; and the claim, also made by the theory, that exposure to many years of higher education is not a major cause of the liberalism of graduate students. We find support for all three claims, with ambiguity only on the question of whether the greater propensity of those on the left to attend graduate school results from personality differences.

Within the particular fields I’m studying this is even more true. For public policy — speaking very broadly — if you’re conservative and mostly want to cut government then why study how to do government better? Why not study business or law instead? And public health has traditionally been a field that  favors a lot of government intervention too.


01 2012

Platform evaluation

Cesar Victora,  Bob Black,  Ties Boerma, and Jennifer Bryce (three of the four are with the Hopkins Department of International Health and I took a course with Prof Bryce) wrote this article in The Lancet in January 2011: “Measuring impact in the Millennium Development Goal era and beyond: a new approach to large-scale effectiveness evaluations.” The abstract:

Evaluation of large-scale programmes and initiatives aimed at improvement of health in countries of low and middle income needs a new approach. Traditional designs, which compare areas with and without a given programme, are no longer relevant at a time when many programmes are being scaled up in virtually every district in the world. We propose an evolution in evaluation design, a national platform approach that: uses the district as the unit of design and analysis; is based on continuous monitoring of different levels of indicators; gathers additional data before, during, and after the period to be assessed by multiple methods; uses several analytical techniques to deal with various data gaps and biases; and includes interim and summative evaluation analyses. This new approach will promote country ownership, transparency, and donor coordination while providing a rigorous comparison of the cost-effectiveness of different scale-up approaches.

Monday Miscellany

  • Tara Parker-Pope writes “The Fat Trap,” a long essay in the New York Times on obesity. (And here’s a thoughtful response from Rod Dreher.) Update: also see this by Aaron Carroll on the same subject.
  • Dave Algoso reminds us that — whether with Google Reader or in international development — “if you’re not paying for it then you’re not the customer. You’re the product.”
  • The Economist explores cases where militaries own sizable chunks of the non-military economy, including Egypt and Iran.
  • Wronging Rights sighs: “human rights for gays somehow still a point of controversy.”
  • How does Prozac work? In short, we don’t know.
  • Have you seen this incredible chart from Mother Jones on the recent history of bank mergers?
  • A fascinating and terrifying story about a cargo container emitting massive radiation and how no one could decide what to do with it.


01 2012