ICPSR Social Science Data Repository

In a recent visit to the library (looking for old Haitian census data) a librarian helped me use the Inter-University Consortium for Political and Social Research data repository.  This group collects and curates a huge database of datasets and facilitates resource exchanges across universities (I used it to obtain hard copies of old censuses from Olin Library at Cornell). A link has been added to the Meta-Resources Page.

Nature Climate Change Publishes first articles

Nature Climate Change is a new, high-profile and interdisciplinary journal focused on climate change research.  Its first research articles were released last week, abstracts below.

Nonlinear heat effects on African maize as evidenced by historical yield trials

David B. Lobell, Marianne Bänziger, Cosmos Magorokosho & Bindiganavile Vivek

New approaches are needed to accelerate understanding of climate impacts on crop yields, particularly in tropical regions. Past studies have relied mainly on crop-simulation models or statistical analyses based on reported harvest data3, 4, each with considerable uncertainties and limited applicability to tropical systems. However, a wealth of historical crop-trial data exists in the tropics that has been previously untapped for climate research. Using a data set of more than 20,000 historical maize trials in Africa, combined with daily weather data, we show a nonlinear relationship between warming and yields. Each degree day spent above 30 °C reduced the final yield by 1% under optimal rain-fed conditions, and by 1.7% under drought conditions. These results are consistent with studies of temperate maize germplasm in other regions, and indicate the key role of moisture in maize’s ability to cope with heat. Roughly 65% of present maize-growing areas in Africa would experience yield losses for 1 °C of warming under optimal rain-fed management, with 100% of areas harmed by warming under drought conditions. The results indicate that data generated by international networks of crop experimenters represent a potential boon to research aimed at quantifying climate impacts and prioritizing adaptation responses, especially in regions such as Africa that are typically thought to be data-poor.

Perceptions of climate change and willingness to save energy related to flood experience

A. Spence, W. Poortinga, C. Butler & N. F. Pidgeon

One of the reasons that people may not take action to mitigate climate change is that they lack first-hand experience of its potential consequences. From this perspective, individuals who have direct experience of phenomena that may be linked to climate change would be more likely to be concerned by the issue and thus more inclined to undertake sustainable behaviours. So far, the evidence available to test this hypothesis is limited, and in part contradictory. Here we use national survey data collected from 1,822 individuals across the UK in 2010, to examine the links between direct flooding experience, perceptions of climate change and preparedness to reduce energy use. We show that those who report experience of flooding express more concern over climate change, see it as less uncertain and feel more confident that their actions will have an effect on climate change. Importantly, these perceptual differences also translate into a greater willingness to save energy to mitigate climate change. Highlighting links between local weather events and climate change is therefore likely to be a useful strategy for increasing concern and action.

Social Conflict in Africa Database

The University of Texas at Austin has put together a new dataset to support conflict research in Africa. Some nice features of this dataset are that they code many types of conflict, not just civil wars, and that the conflicts have "issues" associated with them (eg. "democracy" or "environmental degradation"). The database is searchable and downloadable, and the website has some nice discussions of ongoing research projects.

The Social Conflict in Africa Database (SCAD) is designed to provide users with a comprehensive, methodologically rigorous resource for analyzing social conflict events across the African continent, including all countries with a population of more than 1 million.  It compiles events reported by the Associated Press and Agence France Presse from 1990-2009.  SCAD is designed for use by academic researchers, as well as by journalists, non-governmental organizations, policy makers, and others interested in African politics.

Each record in SCAD refers to a unique social conflict event.  To define an event, the researchers determined the principal actor(s) involved, the target(s), as well as the issues at stake.  Events can last a single day or several months.  A conflict is coded as a single event if the actors, targets, and issues are the same and if there is a distinct, continuous series of actions over time.

Some interesting plots from the website:

Sustainable Development Articles

Our colleague James Rising points us to his newly coded up creation Sustainable Development Articles:

I put together a site for collecting Sustainable Development papers and articles! This is for all of us who wish there were a better way to find, share, and keep track of good SD reading material.

[...]

If you use Mendeley [previously blogged on FE here] for organizing your papers, you can drag-and-drop papers into the site by joining the Mendeley group "Sustainable Development to sd.existencia.org Bridge" and putting the papers there. With a delay (~ 1 hr), they'll show up on the site!

There's already a bunch of great stuff up there. Go take a look.

Japan's damage

The NYT has put together a solid interactive site to see aerial images before and after the recent events.

Welcome High School for Environmental Studies students!

Greetings and welcome to students from the High School for Environmental Studies!

Sol and I have gotten wind that you're going to be our online guests leading up to our talk on April 5th. We're very happy to have you guys here and hope you're as excited as we are. We've set up this page up so you have an easy and accessible place to find out more about climate change, sustainable development, and our research. In particular you might want to check out any post tagged with the HSES tag, since those are going to be oriented more specifically towards you. Please feel free to check back every now and then for new content and links, and if you have any questions don't hesitate to email either of us (Jesse: jka2110@columbia.edu Sol: smh2137@columbia.edu).

Assorted reference links:

• The Sustainable Development Ph.D. program at Columbia
• Jeffrey Sachs and Joseph Stiglitz are our program's (very interesting) co-founders
• Jesse and Sol's personal websites
• What is economic development?
• What is sustainable development?
• Understanding the science behind climate change

Previous posts on the blog that you might like:

• Understanding nuclear accidents
• How we know what we know about the climate
• Urban ecology doesn't care about your locavore agenda
• The structure of human knowledge
• Risk denialism and the costs of prevention

General advice on getting ready for college, research, environmentalism, etc.:

• Study Hacks is a great resource for students of any age, but especially for those of you preparing for (and stressing out about) college
• What is the purpose of research?
• Sustainability as a simple concept: The parable of St. Matthew Island

Understanding Nuclear Accidents

As if the direct damages from the Sendai earthquake / tsunami weren't enough, there's now ample concern that one of the nuclear power plants damaged by the quake might melt down. Ed Lyman of the Union of Concerned Scientists' All Things Nuclear blog has an overview of what's going on and how this could make an already horrific disaster worse:

I have done considerable analysis on the safety risks associated with using MOX fuel in light-water reactors. The use of MOX generally increases the consequences of severe accidents in which large amounts of radioactive gas and aerosol are released compared to the same accident in a reactor using non-MOX fuel, because MOX fuel contains greater amounts of plutonium and other actinides, such as americium and curium, which have high radio-toxicities.

Because of this, the number of latent cancer fatalities resulting from an accident could increase by as much as a factor of five for a full core of MOX fuel compared to the same accident with no MOX. Fortunately, as noted above, the fraction of the fuel in this reactor that is MOX is small. Even so, I would estimate this could cause a roughly 10% increase in latent cancer fatalities if there were a severe accident with core melt and containment breach, which has not happened at this point and hopefully will not.

They also have an excellent two page pdf describing how nuclear power plants work and why they can be so unstable.

More broadly, one of our better estimates of the long-term impacts of nuclear fallout was actually done by Doug Almond, one of the SDev Ph.D. program's core faculty. From his 2009 Quarterly Journal of Economics article with Lena Edlund and Mårten Palme:

We use prenatal exposure to Chernobyl fallout in Sweden as a natural experiment inducing variation in cognitive ability. Students born in regions of Sweden with higher fallout performed worse in secondary school, in mathematics in particular. Damage is accentuated within families (i.e., siblings comparison) and among children born to parents with low education. In contrast, we detect no corresponding damage to health outcomes. To the extent that parents responded to the cognitive endowment, we infer that parental investments reinforced the initial Chernobyl damage. From a public health perspective, our findings suggest that cognitive ability is compromised at radiation doses currently considered harmless.

There's accompanying video of the Chernobyl plume's spread here. And not to be terribly alarmist, but western North America is directly downwind from Japan.

Does Daylight Saving Time Save Energy?

While reflecting on my loss of sleep this past weekend, I found this working paper from a few years ago:

Does Daylight Saving Time Save Energy? Evidence from a Natural Experiment in Indiana

Matthew J. Kotchen, Laura E. Grant
NBER Working Paper No. 14429

Abstract: The history of Daylight Saving Time (DST) has been long and controversial. Throughout its implementation during World Wars I and II, the oil embargo of the 1970s, consistent practice today, and recent extensions, the primary rationale for DST has always been to promote energy conservation. Nevertheless, there is surprisingly little evidence that DST actually saves energy. This paper takes advantage of a natural experiment in the state of Indiana to provide the first empirical estimates of DST effects on electricity consumption in the United States since the mid-1970s. Focusing on residential electricity demand, we conduct the first-ever study that uses micro-data on households to estimate an overall DST effect. The dataset consists of more than 7 million observations on monthly billing data for the vast majority of households in southern Indiana for three years. Our main finding is that -- contrary to the policy's intent -- DST increases residential electricity demand. Estimates of the overall increase are approximately 1 percent, but we find that the effect is not constant throughout the DST period. DST causes the greatest increase in electricity consumption in the fall, when estimates range between 2 and 4 percent. These findings are consistent with simulation results that point to a tradeoff between reducing demand for lighting and increasing demand for heating and cooling. We estimate a cost of increased electricity bills to Indiana households of $9 million per year. We also estimate social costs of increased pollution emissions that range from $1.7 to $5.5 million per year. Finally, we argue that the effect is likely to be even stronger in other regions of the United States.

pooreconomics.com

Abhijit Banerjee and Esther Duflo have put together what promises to be an excellent new book collecting the array of new advances made in development economics: Poor Economics.

The book isn't out yet, but its website sets a new standard for how academics present their work.  It has interactive maps, datasets and a collection of quality studies (each chapter has a long list of relevant reading).

Check it out: pooreconomics.com

Stata blog post on understanding matrices (with bonus Stata cheat sheet)

William Gould on Stata's blog (previously mentioned here) has two great posts (here and here) on the intuition behind matrices and regression coefficients. The section on near-singular matrices is characteristically nice:

Singular matrices are an extreme case of nearly singular matrices, which are the bane of my existence here at StataCorp. Here is what it means for a matrix to be nearly singular: [see figure]

Nearly singular matrices result in spaces that are heavily but not fully compressed. In nearly singular matrices, the mapping from x to y is still one-to-one, but x‘s that are far away from each other can end up having nearly equal y values. Nearly singular matrices cause finite-precision computers difficulty. Calculating y = Ax is easy enough, but to calculate the reverse transform x = A-1y means taking small differences and blowing them back up, which can be a numeric disaster in the making.

Both posts are great and I recommend them for anyone struggling with the intuition behind what exactly you're doing when you type in reg y x.

As an added bonus, earlier this week I stumbled across Kenneth Simon's excellent pdf cheat sheet of Stata commands for intermediate / advanced econometrics, here. I was trying to figure out a way to do something cute with distributed lag models and post-estimation tests, but the sheet covers everything from the simple but important (e.g., the difference between gen old = age >= 18 and gen old = age >= 18 if age<. ) to the arcane but potentially important (e.g., nonlinear hypothesis testing). If you're in applied work and use Stata I highly recommend flipping through it. I've already found several useful techniques I wasn't even aware existed.

March 11 Pacific Tsunami

NOAA has put together a nice technical site with model output and gauge readings from the tsunami on Friday.  The EVL used the data to make the graphic on the top, the NYT put together the graphic on the bottom:

A team at the NYTimes has also put together a nice interactive explanation about how tsunamis are generated and an interactive map with images of the damage.

Maps + Data Presentation

Since Sol recently posted on both NOAA's lovely data visualization labs and an assortment of map resources, I figured it might be worth pointing our readers to Cartastrophe. From the site's about page:

There are a lot of bad maps out there. They lurk in brochures, on company websites, and in magazines. They confuse, they miscommunicate, and they make it hard to learn anything about the world. Sometimes they leave off Sicily. They’re made by people who have to rush against tight deadlines, by people who are pressured by their bosses or clients to make bad design choices because it “looks cool,” and by people who were thrust into map-making jobs without any training.

[...]

We learn a lot from seeing what went wrong in someone else’s experience. I hope to amuse, but also to educate — to help people (myself included) understand what the elements of a good map are. And maybe, just maybe, if people are better able to understand what makes up a bad map, they’ll start demanding better ones.

The site is effectively the cartographic counterpart to Andrew Gelman's consistently superb data presentation critiques, and offers a huge amount of useful and thoughtful advice. Highlights:

• Texas grows 70% each year
• A village floating off the coast
• The vanishing kingdom

The last link is particularly nice for its reminder that as much as many of us love Google maps (I have difficulty imagining how I went through life before it...) it can still contain major errors.

Earth Magazine Article

A recent article of mine came out in Earth Magazine.  Its an abridged description of my PNAS paper, which I described in an earlier post.

The best part is that on their main site

www.earthmagazine.org

they have a voluntary "visitors poll" (I mentioned a different poll in an earlier post) asking visitors if high temperatures affects their productivity. The results at the time of this posting are:

For those interested in the large (but sometimes statistically underpowered) literature on thermal stress and human productivity, here is a review from the Indoor Air Quality Handbook (2001).

Map resources

I spoke with some librarians today who pointed me to two excellent online resources for historical maps, the University of Texas Map Library and the David Rumsey Map Collection.  There is so much untapped information on these sites its overwhelming.  Below were two favorites that I found on Rumsey's site.

The Distribution of Wealth, 1870

Ranking of States by Income, Debt, Literacy, etc, 1880

Bibliometrics and book shrink

In the middle of doing a bunch of bibliometrics work I came across a site called BookShrink that parses a text to choose the sentences in it that are most representative of the whole. The alogorithm basically assigns a score to each sentence based on the total frequency count of all words in the book and then normalizes by sentence length. So no, it doesn't look like it has anything positional and no, it doesn't condense the book into Cliff Notes-style summary (and it doesn't read pdf's, so don't think you're getting out of doing your lit review using just some bash scripts) BUT it is pretty cool. Loading in the entirety of The Wealth of Nations yields:

1 (1.000000): The taxes upon expense, therefore, which fall chiefly upon that of the superior ranks of people, upon the smaller portion of the annual produce, are likely to be much less productive than either those which fall indifferently upon the expense of all ranks, or even those which fall chiefly upon that of the inferior ranks, than either those which fall indifferently upon the whole annual produce, or those which fall chiefly upon the larger portion of it.

2 (0.961065): I shall endeavour to give the best account I can, first, of those taxes which, it is intended should fall upon rent; secondly, of those which, it is intended should fall upon profit; thirdly, of those which, it is intended should fall upon wages; and fourthly, of those which, it is intended should fall indifferently upon all those three different sources of private revenue.

3 (0.765899): From the end of the first to the beginning of the second Carthaginian war, the armies of Carthage were continually in the field, and employed under three great generals, who succeeded one another in the command; Amilcar, his son-in-law Asdrubal, and his son Annibal: first in chastising their own rebellious slaves, afterwards in subduing the revolted nations of Africa; and lastly, in conquering the great kingdom of Spain.

4 (0.708201): You must pay, too, for the tax upon the salt, upon the soap, and upon the candles which those workmen consume while employed in your service; and for the tax upon the leather, which the saltmaker, the soap-maker, and the candle-maker consume, while employed in their service.

...

No, nothing about pins, but still pretty interesting.

NOAA Environmental Visualization Laboratory

Just completing my data visualization hat trick for the week.  A colleague of mine, Amir Jina, recently pointed me to what is now one of my favorite websites: NOAA's Environmental Visualization Laboratory.

The group takes huge quantities of real-time data and transforms it into beautiful images designed to teach students and the public about the global environment. Perhaps most impressive is the constant stream of new images.  Some elegant highlights below.

Nitrogen dioxide concentrations showing China's superlative industrial pollution.

The absence of atmospheric water vapor over the equatorial Pacific illustrates the current La Nina.

3D plot of snow-depth in the US following some of the recent storms (related to the La Nina).

Composite image of some 2010 hurricanes.

North Atlantic sea surface temperatures were extraordinarily warm this past October.

Cropscape Data Visualization

Micahel Roberts recently sent me a link to this relatively new data browser for land-use in the US, produced by the National Agricultural Statistical Service. Its not available for all years, but the resolution is impressive, allowing you to zoom in so you can see the individual fields of farmers.

The announcement of the dataset was here:

“CropScape delivers data visualization tools directly into the hands of the agricultural community without the need for specialized expertise, GIS software or high-end computers,” said Mark Harris, NASS Research and Development Division director. “This information can be used for addressing issues related to agricultural sustainability, land cover monitoring, biodiversity and extreme events such as flooding, drought and hail storm assessment.”

NASS produced the 2010 CDL using satellite image observations at 30-meter (0.22 acres per pixel) resolution and collected from the Resourcesat-1 Advanced Wide Field Sensor (AWiFS) and Landsat Thematic Mapper. The collection of images was categorized using on-the-ground farm information including field location, crop type, elevation, tree canopy and urban infrastructure. All prior CDL products dating back to 1997 are also hosted by CropScape.

CropScape was developed in cooperation with the Center for Spatial Information Science and Systems at George Mason University, Fairfax, Va. The research and development ofCropScape and the NASS partnership with George Mason University reflect NASS’s continued commitment to improve U.S. agricultural production, sustainability and food security. 

CropScape is operated by NASS’s Research and Development Division and hosted and maintained by the Center for Spatial Information Science and Systems at George Mason University. For more information about CropScape, and the Cropland Data Layer visit http://nassgeodata.gmu.edu/CropScape.

Refugee flow visualization

A colleague and I are doing some work on refugees and ran across this excellent vizualization of UNHCR data here. This is how they describe it:

Since 1950, the United Nations High Commissioner for Refugees is mandated with the coordination of aid and assistance for refugees worldwide. According to its self-description, its primary purpose is to safeguard the rights and well-being of refugees. Over 6,000 people in more than 110 countries work for the UNHCR. Founded in 1951 as a means to assist the more than one million people who were still uprooted after World War II, the agency's mandate covered about 10 million refugees in 2009. This visualization attempts to give a comprehensive overview of the phenomenon of flight and expulsion, an ongoing issue of global scale and extreme complexity. 

Based on the annual UNHCR Refugee Report, the application allows views from different perspectives on the extensive dataset, highlighting different aspects. The idea for this visualization originated from a class project on the topic of mapping global tendencies at Potsdam University of Applied Sciences in 2008. The current application's interface was completely rebuilt in late 2009.

What it means to be in a nondemocratic developing country

Like I assume most of the people who read this blog, I've been watching events unfold in Egypt with a mix of (mostly) hope and (some) worry. Ignoring for the moment possible outcome trajectories, the specifics of what's been going on, the response from other countries, and everything else, I think it's interesting to focus for a second on why and how Egypt got here:

"... a carnival atmosphere descended on the square, where vendors offered food at discount prices and protesters posed for pictures in front of tanks scrawled with slogans like, '30 years of humiliation and poverty.'"

That's from an online NY Times article from yesterday that's been getting continuously updated (and now no longer shows the original quote). The set of events that have to go down to bring about the kind of social unrest we're seeing in Egypt aren't trivial. People routinely toss around the idea of "revolution" when discussing topics like a change in US political party or new regulations (e.g., of gun control, carbon taxation, health care...) but the costs of revolution, in particular in terms of the uncertainty of its outcome, are huge. So I think it bears thinking about for a second:

30 YEARS of humiliation and poverty. Notoriously brutal secret police. Elite capture. Enough frustration to push your way across a bridge guarded by hundreds of cops willing to turn a water cannon on you.

We often talk about development, its constraints, and the various political, economic, and historical forces which result in countries being "developed" or not. Sometimes those conversations can get very abstract. It's worth remembering that being in a typically underdeveloped, undemocratic country means dealing on a day to day basis with issues so debilitating and frustrating that you're motivated to spray paint your grievances on the side of a tank.

*Note: the graffiti on the side of the tank says "Down with Mubarak," and comes from Ramy Raoof's flickr stream, here.

Weather-driven pirate risk maps

A variety of sources point out that Naval Research Labs' James Hansen* has come up with a piracy-risk model that takes as its two major sources of input current and forecasted weather and in-field reports on pirate activity:

"Usually, I'm doing theoretical stuff down in the weeds," said Hansen, a Seattle-area native and applied mathematician at the Naval Research Laboratory in Monterey, Calif. "This is the only project where I can actually show pictures of the impact," he said, projecting images of Somali boatmen armed with missile-launchers and automatic weapons.

The quote is from an article in the Seattle Times about a presentation that Hansen gave at the American Meteorological Society meeting. The model is driven by the fact that most if not all modern piracy depends on small, fast boats that can evade long-distance detection and can outpace larger slower cargo ships. In heavy weather the boats can't operate. Combine weather forecasts with observed pirate activity and voilà.

I can't locate any sort of working paper at present, so if any of y'all locate it please do send it to me. And as I wrote to the sdev-internal email list: someone please please please write a paper using this ASAP. Just be careful of your exclusion restrictions.

* As Sol points out: "How many climate scientists are named James Hansen? I now know of 3."