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(Mostly) Vindicated: Euclidean measures of distance are just as good as high priced, fancy measures

DistancePlotsITNIn my seminal paper, “Distance to health services influences insecticide-treated net possession and use among six to 59 month-old children in Malawi,” I indicated that Euclidean (straight line) measures of distance were just as good as more complicated, network based measures.

I didn’t include the graph showing how correlated the two were, but I wish I had and I can’t find it here my computer.

Every time I’ve done presentations of research of the association of distances to various things and health outcomes, someone inevitably asks why I didn’t use a more complex measure of actual travel paths. The idea is that no one walks in a straight line anywhere, but rather follows a road network, or even utilizes a number of transportation options which might be lost in a simple measure.

I always respond that a straight line distance is as good as any other when investigating relationships on a coarse scale. Inevitably, audiences are never convinced.

A new paper came out today, “Methods to measure potential spatial access to delivery care in low- and middle-income countries: a case study in rural Ghana” which compared the Euclidean measure with a number of more complex measurements.

The conclusion confirmed what I already knew, that the Euclidean measure is just as good in most cases, and the pain and cost of producing sexy and complicated ways of calculating distance just isn’t worth it.

It’s a pretty decent paper, but I wish they had put some graphs in to illustrate their points. It would be good to see exactly where the measures disagree.

Background
Access to skilled attendance at childbirth is crucial to reduce maternal and newborn mortality. Several different measures of geographic access are used concurrently in public health research, with the assumption that sophisticated methods are generally better. Most of the evidence for this assumption comes from methodological comparisons in high-income countries. We compare different measures of travel impedance in a case study in Ghana’s Brong Ahafo region to determine if straight-line distance can be an adequate proxy for access to delivery care in certain low- and middle-income country (LMIC) settings.

Methods
We created a geospatial database, mapping population location in both compounds and village centroids, service locations for all health facilities offering delivery care, land-cover and a detailed road network. Six different measures were used to calculate travel impedance to health facilities (straight-line distance, network distance, network travel time and raster travel time, the latter two both mechanized and non-mechanized). The measures were compared using Spearman rank correlation coefficients, absolute differences, and the percentage of the same facilities identified as closest. We used logistic regression with robust standard errors to model the association of the different measures with health facility use for delivery in 9,306 births.

Results
Non-mechanized measures were highly correlated with each other, and identified the same facilities as closest for approximately 80% of villages. Measures calculated from compounds identified the same closest facility as measures from village centroids for over 85% of births. For 90% of births, the aggregation error from using village centroids instead of compound locations was less than 35 minutes and less than 1.12 km. All non-mechanized measures showed an inverse association with facility use of similar magnitude, an approximately 67% reduction in odds of facility delivery per standard deviation increase in each measure (OR = 0.33).

Conclusion
Different data models and population locations produced comparable results in our case study, thus demonstrating that straight-line distance can be reasonably used as a proxy for potential spatial access in certain LMIC settings. The cost of obtaining individually geocoded population location and sophisticated measures of travel impedance should be weighed against the gain in accuracy.

Can the use of technology in surveys change the nature of responses?

In the past, surveys were done on paper, either through a designed questionnaire or by someone frantically writing down interview responses. When computers came around, people would be hired to type in responses for later analysis.

Nowadays, with the advent of cheap and portable computing, research projects are rapidly moving toward fully digital methods of data collection. Tablet computers are easy to operate, can be cheaply replaced, and now can access the internet for easy uploading of data from the field.

Surveyors like them because large teams can be spread out over a wide space, data can be completely standardized and the tedious process of data entry can be avoided.

Of interest to me, however, is whether the technology is influencing the nature of the responses given. That is, will someone provide that same set of responses in a survey using digital data collection methods as in a paper survey?

Recently, we attempted using a tablet based software for a small project on livestock possession and management on Mbita Point in Western Kenya. I intended it as a test to see if a particular software package might be a good fit for another project I`m working on (the one that`s paying the bills).

We had only limited success. The survey workers found the tablets clunky and a number of problems with the Android operating system made it more trouble than the survey was actually worth. Of interest, though, was how the technology distracted the enumerators from their principle task, which was to collect data.

Enumerators would become so wrapped up in trying to navigate the various buttons and options of the software that they couldn`t effectively concentrate on performing the survey. Often they appeared to skip questions out of frustration or would just frantically select one of the many options in the hope of moving on to the next one.

In a survey of more than 100 questions, the process started taking far more time than households were willing to give. We eventually had to abandon the software and revert to a paper based method.

Surveys went from lasting more than one hour, to taking under 30 minutes. Workers were more confident and had more time to interact with the respondents. Respondents had more of an opportunity to ask questions and consider the meaning of what they were being asked. They offered far more information than we expected and felt that they were participating in the survey as a partner and not just as a passive victim.

One of our enumerators noted that people react differently to a surveyor collecting data on the tablets than with paper. She described collecting data with technology as being “self absorbed” and alienating to the respondents. Collecting data on paper, however, was seen as a plus. “They can see me writing down what they say and feel like their words are important.”

I`m thinking that the nature of the responses themselves might be different as well. Particularly with complex questions of health and disease, often the surveyors will have to explain the question and give a respondent a chance to ask for further clarification. Technology appears to inhibit this process, perhaps compromising the chance for a truly reasoned response.

While I am absolutely not opposed to the use of technology in surveys, I think that the survey strategy has to be properly thought through and the challenges considered. At the same time, however, data collection is a team effort and requires a proper rapport between community members and surveyors who often know each other.

Is technology restricting our ability to gather good data? Could the use of technology even impact the nature of the response by pushing them in ways which really only tell us what we want to believe rather than what actually exists?

Do field research projects do the world any good?

IMG_3931It’s a reasonable question to which no one really has an answer. I work in a field site located on Lake Victoria, the office of which is based out of the International Centre for Insect Physiology and Ecology (ICIPE) station on Mbita Point.

We do malaria field surveys and have a large health and demographic surveillance system that has monitored births, deaths, migration and health events of nearly 50,000 people over the past six years.

The goals of the project are to monitor changes in demographics, outbreaks and changes in the dynamics of the transmission of infectious diseases and gauge the effectiveness of interventions.

While I view those as scientifically important, I don’t think that people on the ground experience any immediate benefit from scientific research activities. In fact, I’m pretty sure that, unless they’re getting a free bednet, it’s mostly an annoyance. Of course, we appreciate their cooperation and they are free to tell us to bugger off at anytime.

We are seeing rapid declines in malaria incidence, infant mortality and fertility in the communities we study. This is, of course, cause for celebration. Less kids are dying and people are having fewer of them.

In fact, the shift in the age distribution was so dramatic from 2011 to 2012, that we thought it an aberration of the data: the mean age of 12,000 people rose nearly two years from the beginning of 2011 to the latter part of 2012. Old people died off, and fewer babies were there to replace them, resulting in an upward shift in the age distribution. Cause for celebration in an area where women normally have anywhere from 5 to 10 children, who often end up malnourished, poorly housed and uneducated.

But we have to ask ourselves, how much of this is representative of trends in communities similar to the ones we study and how much is directly influenced by the presence of the research station itself?

A recent article in Malaria Journal documents the positive impacts that a research facility had on the local community:

To make the community a real partner in the centre’s activities, a tacit agreement was made that priority would be given to local people, in a competitive manner, for all non-professional jobs (construction workers, drivers, cleaners, field workers, data clerks, and others). Of the 254 people employed at the CRUN, about one-third come from Nanoro. This has strengthened the sense of ownership of the centre’s activities by the community. Through the modest creation of new jobs, CRUN makes a substantial contribution to reducing poverty in the community. In addition, staff members residing in Nanoro contribute to the micro-economy there.

Another crucial benefit for Nanoro and CRUN stemming from their productive engagement was electrification for the area. This was made possible by the mayor of Nanoro leading the negotiations for extending the national electrical grid to the CRUN, and with it, to the village of Nanoro. Electrification spurred a lot of economic activity and social amenities that enhance the wellbeing of the community, such as: (1) improved water supply through use electricity instead of generator; (2) ability to use electrical devices, such as fans during the hot season (when temperatures can reach 45-47°C), lighting so students can study at night, the use of refrigeration to safely store food and the extension of business hours past sunset.

Health care services have been improved through CRUN’s new microbiology laboratory. Before this laboratory was established, local patients had to travel about 100 km to the capital city, Ouagadougou, for the service.

This agrees with my experience on Lake Victoria. The presence of the research facility (built originally in the 1960’s) and the subsequent scale up of research activities has been transformative for the area. As more and more people have moved to the area, a bridge to Rusinga Island has been built, two new ferry routes have been installed, the existing ferries have been upgraded, power has been extended to the area and finally, after years of waiting, a paved road has been built from Kisumu to Mbita Point.

..which brings back me to my initial question. It is clear that the building of research facilities can be a major spur for economic development and economic activity in a previously desolate and marginalized area. In case of Mbita Point, it is possible that these gains can be sustained even following an eventual cessation of research activities and strangled funding. In this sense, field research projects are doing at least some of the world good.

However, the gains which these communities are experience really have little to do with the research projects themselves and more to do with the influx of employment and infrastructure that come with research stations and research projects. This is non-controversial and I’m sure that the locals appreciate it.

But the quality and goals of research need to be assessed. Are the results we are seeing truly representative of communities which may be similar to the Mbita Point of the past? Are we unnecessarily influencing the outcomes of the research and then perhaps inappropriately generalizing them to contexts which little resemble our target communities? From a scientific perspective, this is troubling.

Of greater concern, however, are we claiming that gains against malaria are being made, when in fact, morbidity and mortality in communities we haven’t looked at is increasing? This could result in a dangerous shift away from scaled up ITN distributions or even a total reduction in international funding. If this happens, kids will die.

Obokata Haruko: Shoddy scientist or scapegoat?

photo_2I know very little about lab sciences. A few months ago, Obokata Haruko, graduate of Waseda University and researcher at the Riken Center for Developmental Biology in Japan, discovered something “too good to be true.” She found a way of creating pluripotent cells, that is stem cells which can become anything, without the awful side effect of inducing cancer in a vertebrate host. Though my knowledge of such matters is sadly lacking, from what I understand, virae are usually used to induce the cell to convert, which can make the cell unstable, and likely to turn cancerous. Obokata discovered that the cell could be manipulated merely by stressing them with pressure.

The results followed the peer review process, were rejected once, and, after revising and resubmitting, were eventually published in Nature. Soon thereafter, the results were challenged and it was discovered that the images accompanying the paper did not represent the content of the paper and had likely been lifted from her doctoral dissertation. Obokata was disgraced.

Yesterday, an article appeared which claimed that even more improprieties were found in Obokata’s doctoral thesis and that she has formally requested that her dissertation be withdrawn. She supposedly lifted portions of her introduction from the NIH website without attribution and had doctored images. Even some of the chapter bibliographies were suspicious:

Each chapter in the dissertation has a separate bibliography. For chapter 3, there is a bibliography of 38 references even though there are no footnotes in that chapter. The bibliography contains the authors of the material referred to, the title, the journal and the pages on which the original article appeared.

However, the bibliography in question is almost exactly the same as the first 38 items in a bibliography containing 53 reference materials that was published in 2010 in a medical journal by researchers working at a Taiwanese hospital.

It is entirely possible that Obokata is a shoddy researcher. Actually, it’s quite likely given the mountain of evidence against her. What isn’t clear, is how her mentors allowed her train wreck of a career to happen. Research doesn’t occur in a box. I’d certainly be entirely happy if no one at all ever looked at my dissertation again (outside of the published papers from it). But, one would assume that the most egregious of infractions would be caught by her committee members (and her co-authors) before the work goes into print.

It’s worth nothing that Obokata, like a lot of academics, is quite odd. She had her lab repainted pink and yellow, and would don a Japanese smock more characteristic of kindergarten teachers rather than a traditional lab coat. Though I encourage such behavior, I’m not sure that her eccentric style is doing her career any favors at this point.

This incident brings more than a few conflicting ideas to mind.

First, Japan is a terrible, awful place to be a woman in a professional position. In fact, Japan is pretty much just a terrible place to be a woman at all. In terms of women’s empowerment, wages, education and political representation, Japan is 101st out of 135 countries, well under less developed countries like Kenya, El Salvador, Bangladesh and Indonesia, and among the worst in all of Asia.

Once, I remember when I was visiting Japan, a tenured faculty member who happened to be female was tasked with serving us men tea. I was enraged.

Though Obokata is likely less than professional, professionals are made, not born. I can imagine that, given her reproductive capabilities, her mentors refused to take her seriously, and slacked on their most important job, which was to create and nurture a responsible and talented scientist.

Of course, Obokata, though likely a victim of shoddy mentoring, has to shoulder some of the blame. Shoddy mentors create shoddy students, but shoddy students still have to take responsibility for their own actions. But I can’t help but thinking that it’s interesting that a young female is taking the heat for what should be a collective fuck up.

Obokata is currently being eviscerated in the press. After making numerous appearances on television as an eccentric though brilliant scientist, her downfall has brought out the worst. Many are alleging that Obokata slept with her mentors to attain her position (despite being trained at Harvard), following a narrative that women can’t attain privileged positions without having sex with someone. The vile depths of the interweb are even speculating that Obokata will start making porn, a common standby career for fallen actresses and swimsuit idols, again following a narrative that women are never degraded enough.

Does Obokata deserve the brutal punishment she’s receiving? While scientists need to held accountable for their work, given the amount of shoddy research out there, I would say that Obokata is probably being treated rather unfairly. It would seem though, that the extreme nature of her punishment is due to her gender, her age and the fact that she was unlucky enough to appear on Japanese television.

Cell phone banking in Kenya protects public health

MPESAIt’s rare that I read an academic paper I can get really, really excited about, but this is one of them.

Researchers at Georgetown and MIT have shown that transactions over M-PESA, an African phone banking service can help struggling households when faced with a sudden illness, weather event or economic shock.

We explore the impact of reduced transaction costs on risk sharing by estimating the effects of a mobile money innovation on consumption. In our panel sample, adoption of the innovation increased from 43 to 70 percent. We find that, while shocks reduce consumption by 7 percent for nonusers, the consumption of user households is unaffected. The mechanisms underlying these consumption effects are increases in remittances received and the diversity of senders. We report robustness checks supporting these results and use the four-fold expansion of the mobile money agent network as a source of exogenous variation in access to the innovation.

M-PESA is a cel phone based banking system which allows users to send and receive money to friends and family. Transactions can be small; most users are transferring less than $10 at a time. Users are charge about $.40 to transfer money and a percentage to withdraw. It is free to deposit money into the system.

Anyone can be an M-PESA agent. Starting an M-PESA business requires only a small investment so that even extremely rural areas have access to the system. Agents receive a percentage of transaction costs, and often piggy back it onto existing enterprises such as grocery stores and mobile phone shops. M-PESA not only provides a needed service, but has also created profitable business opportunities for people even in isolated rural areas.

The system is wildly popular. Africans are extremely mobile but maintain deep friend and family networks often spread out over wide distances. When a person has trouble, he or she will often turn to family and friends for financial help.

Previously, people would send money by getting on a bus and travelling, or by sending it with friends who might be going to a particular destination. Transportation costs are high ($5 to go a distance of 200km) and often outweigh the amount to be sent. Sending money by hand also incurred risks of loss to theft and misuse.

The number of M-PESA users has skyrocketed since its introduction in 2007. Nearly all adults in Kenya have access to a cel phone now, and the number of M-PESA users is now 70% of all mobile phone users.

Shocks due to illness or negative weather events such as drought can be devastating for a poor household. A single bout of malaria could set a family back as much as a month’s income or more. When poor households lose money, they don’t get it back and successive events can quickly pile up so much so that families will often wait until illness has become too severe to effectively treat.

Jack and Suri, the researchers who conducted the study found that illness shocks can reduce a households consumption by at least 7%. An average household only consumes around $900 a year, nearly half of which is for food. A 7% reduction in consumption could mean that households will simply eat less given a sudden negative event.

M-PESA users, however, experience no reduction in consumption given a sudden health or economic event. Presumably, the ability to transfer money quickly over long distances provides insurance against disaster. Mutual reciprocation allows the system to effectively function to protect against financial disaster.

This has incredible implications for public health. Financial concerns are an incredible barrier to insuring prompt and effective treatment for diseases such as malaria, diarrheal disease and respiratory infections. An efficient system of moving money creates a broader social insurance scheme, protecting the public against the worst and, hopefully, reducing costly advanced treatments and mortality.

M-PESA is a private sector entity, which was never intended as a public health intervention. However, in an area where public sector health delivery is inefficient, underfunded and most broken, a private sector banking initiative could help bolster availability of life saving drugs (for example) by insuring a consistent flow of money. Shops in extremely isolated rural areas will be more likely to stock malaria drugs if they know that customers have the means to pay for them.

This also has incredible implications for development. One of the pillars of the Millennium Development Goals and the recent Rio+20 Conference on Sustainable Development is to insure that the basic health needs of the poorest people on the planet are met. This cannot happen without addressing the greater problem of financial stability of poor households, which requires the participation of the private sector. Covering basic issues of financial movement, security and access to funds by isolated households is a major step to not only helping households which are disproportionately impacted by health and weather events, but also allows flow of cash to poor regions, bolstering local economies.

Science and the importance of failure: What TED talks overlook

I was just reading a transcript of Benjamin Bratton’s takedown of TED, the immensely popular series of talks on science and innovation. Perhaps the word “talk” is a bit too specific. TED is more of a “format” for presenting ideas.

To be clear, I think that having smart people who do very smart things explain what they doing in a way that everyone can understand is a good thing. But TED goes way beyond that.

Let me tell you a story. I was at a presentation that a friend, an Astrophysicist, gave to a potential donor. I thought the presentation was lucid and compelling (and I’m a Professor of Visual Arts here at UC San Diego so at the end of the day, I know really nothing about Astrophysics). After the talk the sponsor said to him, “you know what, I’m gonna pass because I just don’t feel inspired… you should be more like Malcolm Gladwell.”

At this point I kind of lost it. Can you imagine?

Think about it: an actual scientist who produces actual knowledge should be more like a journalist who recycles fake insights! This is beyond popularization. This is taking something with value and substance and coring it out so that it can be swallowed without chewing. This is not the solution to our most frightening problems — rather this is one of our most frightening problems.

I couldn’t agree more. As scientists, we are required to be able to explain our research to the outside world. Aside from the important matter of justifying our existence and use of public funds, some of us would hope that our work improves the world. However, the process of explaining shouldn’t involve unnecessarily dumbing down or overstating the potential impact of our work.

TED demands that every presentation be centered around some success. We have to end the talk on some positive note, proudly declaring that our work went the way we wanted it to and had a profound impact on the world. We are there to create, innovate and inspire.

The trouble is that science is often hardly creative, sometimes not innovative and often wholly uninspiring. Mind you, I don’t consider these to be negatives.

Much of science involved the testing of previously held results, views and conclusions. We aren’t seeking to create something new, but rather to evaluate the validity of what has been created before or commonly assumed. We are pursuing knowledge with the hope of refining how the world sees itself using methods to create hypotheses, gather evidence and rigorous test our assumptions.

The outcome, of course, is that the road of science is paved with failure. We embark on our adventures with money in hand, a plan, the proper tools and the best intentions, but, in most cases, we find out that the money didn’t go as far as we would have liked, the plan was ill-conceived given the realities on the ground, the tools were insufficient and our intentions may have been misplaced. At least, that’s my experience of science.

Again, I don’t see this as a negative. In order to improve our ability to understand the world and potentially ameliorate it’s problems, we are required to fail. A child can’t learn to walk without falling down. I can’t learn how to not offend people in Japanese without offending people more than a few times. I can’t learn how not to bake a cake without creating an inedible mess.

TED talks overlook this process of failure, focusing exclusively on the positives and the successes and, more troubling, the inspirational nature of the work. But then, this is a problem that’s not unique to TED talks. I find that TED talks are really just symptomatic of a broader trend which discourages negative results to the point where scientists troll the data hoping to find at least something that can be labelled “successful.”

Most journals won’t publish papers with negative results and most people don’t want to read them. To me, though, there is as much to learn from a paper which found that the previously held view was correct than one which refutes it. There is as much to know from a project which failed miserably as one which was “successful.” At least in my discipline, where field work under pressing circumstances is the norm, it would be nice to hear where people went miserably wrong. We could waste a lot less time, money and experience a little less frustration.

This success driven culture isn’t, of course, limited to science. It permeates our culture, particularly our children. This young generation (and their parents) appears wholly frightened of failure, potentially to the point of paralysis. If we aren’t careful, we might turn into the stagnant Japan of the 00’s.

TED talks probably have to go. While they worked well in the Gates era where small technological fixes in isolated boxes were thought to solve mankind’s most pressing problems, we need to move on to a format which effectively looks to the process of exploration. We need to know and accept that we will fail and those potential sources of failure need to inform our current strategies.

We need to integrate people of many disciplines for mutual benefit. For example, as a quantitative scientist, I learn a lot from people in the humanities, who often hold viewpoints and perspectives completely different from my own but no less important.

In short, we need more discussion and less posturing. Failure is good because we learn from it. Let’s not let the the scientific forum, as Dr. Bratton noted, becomes like cheap, inspirational, yet myopic and wholly useless megachurches.

A few articles I’m reading 1/10/2014

That’s the first time I’ve typed “2014” all year. Wow.

Here are some articles I’m reading this morning:

1. The news seems to be all over debates on the general shift toward the right in Europe (a feature in a recent issue of the Economist). Specifically, discussion of the tightening of immigration/migration rules are starting to heat up. One analyst has developed models to determine exactly what the long term impact of reduced migration in the UK would be on the overall economy. The results aren’t good.

Our results show that a significant reduction in net migration has strong negative effects on the economy. First, by 2060 in the low migration scenario, aggregate GDP decreases by 11% and GDP per person by 2.7% compared to the baseline scenario (Figure 1). Second, this policy has a significant negative impact on public finances, owing to the shift in the demographic structure after the shock. The total level of government spending expressed as a share of GDP increases by 1.4 percentage points by 2060. This effect requires an increase in the effective labour income tax rate for the government to balance its budget. By 2060 the required increase is 2.2 percentage points. Third, the effect of the higher labour income tax rate is felt at the household level, with average households’ net income declining because of the higher income tax despite the initial increase in gross wages due to lower labour supply. By 2060, the net wage is 3.3% lower in the low migration scenario.

Humans are more mobile in the 21st century than they’ve ever been in human history. Say what one will about globalization, but the reality is that it’s already happened. Cutting the cord on migration would see declines in income in both the developed (through loss of productivity) and developing worlds (through loss of remittances).

2. Niger and France have yet to come to an agreement to the terms of a contract to mine uranium by state owned multi-national giant Areva. Niger would like to increase their share from the current 5% to 12%. Areva is worried about profitability. Not knowing Areva’s operating costs and Niger’s track record of transforming mining revenues into public services, I’m not sure what to think.

France derives 75% of its energy from nuclear power and Areva gets 37% of its uranium from Niger. On top of this, Niger has few other options with which to generate money. The two parties have a lot at stake.

3. Krugman rails on the 50th anniversary of Lyndon Johnson’s War on Poverty. On the surface, it looks to be a bitter failure. Inequality is at an all time high and wages have been slipping for the bottom 25% for decades. Still, Krugman ends on a positive note. The pain we feel now could help spur a new progressive movement. I think he’s probably right. Amid the political circus, We’ve been quietly expanding social programs like Medicaid and it’s going to work out well for us. It’s really easy to be pessimisitic about American politics, but there’s potential light at the end of the tunnel, assuming that progressive can finally get their story straight and the right continues to shoot itself in the face.

4. Groups in Zimbabwe are gearing up to fight over who will succeed the old bastard. I think he’s already dead and we’re actually seeing a robot. I’m not confident that whoever succeeds him will be much better. It’s possible that his poison has been spread so thick, that Zimbabwe, once a rising economic star, will continue to be the inexcusable poster child for African political failure.

At the core of the long running struggle for supremacy in ZANU-PF are two factional groups led by Mujuru and Mnangagwa. Mujuru’s side, sometimes referred to as ‘the moderates’, is a purportedly pro-business and centrist bloc that is seen as attempting to push ZANU-PF politics to the centre and improve relations with the international community.

Mnangagwa’s camp, the so-called ‘hard-liners’ or ‘old guard’, is mostly made up of an elite group believed to have dominated Zimbabwe’s political scene since the 1980s; many assume that this faction would seek to continue Mugabe-style politics, anti-western rhetoric and policies as well as continued authoritarianism.

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