A picture is worth a thousand lives

Kristof's article
I am a strong proponent of spending time on figures, tables and presentations so that important ideas are communicated clearly and succinctly.  The story of this  internal letter written by Nicholas Kristof to his colleagues at the New York Times is a good example of why.
From: Nicholas Kristof 
Subject: the power of art 
in september i traveled with bill gates to africa to look at his work fighting aids there. while setting the trip up, it emerged that his initial interest in giving pots of money to fight disease had arisen after he and melinda read a two-part series of articles i did on third world disease in January 1997. until then, their plan had been to give money mainly to get countries wired and full of computers. 
bill and melinda recently reread those pieces, and said that it was the second piece in the series, about bad water and diarrhea killing millions of kids a year, that really got them thinking of public health. Great! I was really proud of this impact that my worldwide reporting and 3,500-word article had had. But then bill confessed that actually it wasn't the article itself that had grabbed him so much -- it was the graphic. It was just a two column, inside graphic, very simple, listing third world health problems and how many people they kill. but he remembered it after all those years and said that it was the single thing that got him redirected toward public health. 
No graphic in human history has saved so many lives in africa and asia. 
I'm sending you a copy of the story and graphic by interoffice mail. whoever did the graphic should take a bow. 
nick kristof

The info-graphic/table that got Gates' attention.

Apparently, the letter itself is framed and hanging up in the office of the data graphics group at the NYT. h/t Pam.


Attributing climate records to climate change

Stefan Rahmstorf (of RealClimate) and Dim Coumou just published a pretty interesting paper in this week's PNAS, in which they claim last summer's Moscow heat wave was 80% likely to have been due to the observed warming trend in the city. There's a great writeup of the paper (including how and why it contradicts an earlier finding claiming that the heat wave was not due to trends; urban heat island fans should check that one out), but what's particularly noteworthy is the methodology by which they claim attribution of the heat wave to the climate trend:
We develop a theoretical approach to quantify the effect of long-term trends on the expected number of extremes in generic time series, using analytical solutions and Monte Carlo simulations. We apply our method to study the effect of warming trends on heat records. We find that the number of record-breaking events increases approximately in proportion to the ratio of warming trend to short-term standard deviation. Short-term variability thus decreases the number of heat extremes, whereas a climatic warming increases it. For extremes exceeding a predefined threshold, the dependence on the warming trend is highly nonlinear. We further find that the sum of warm plus cold extremes increases with any climate change, whether warming or cooling. We estimate that climatic warming has increased the number of new global-mean temperature records expected in the last decade from 0.1 to 2.8. For July temperature in Moscow, we estimate that the local warming trend has increased the number of records expected in the past decade fivefold, which implies an approximate 80% probability that the 2010 July heat record would not have occurred without climate warming.
I'm still mulling over how much I believe the causal claim here, but I really like the technique of modeling record-breaking as a function of the system's state over time. Some other potential applications immediately spring to mind...


Expert credibility in climate change

While doing a lit review I came across this gem of a paper from last July in PNAS:
Expert credibility in climate change 
Although preliminary estimates from published literature and expert surveys suggest striking agreement among climate scientists on the tenets of anthropogenic climate change (ACC), the American public expresses substantial doubt about both the anthropogenic cause and the level of scientific agreement underpinning ACC. A broad analysis of the climate scientist community itself, the distribution of credibility of dissenting researchers relative to agreeing researchers, and the level of agreement among top climate experts has not been conducted and would inform future ACC discussions. Here, we use an extensive dataset of 1,372 climate researchers and their publication and citation data to show that (i) 97–98% of the climate researchers most actively publishing in the field surveyed here support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers. 
I particularly like the use of independent metrics to verify what my casual observation as a researcher says to be true.

Now, there's clearly potential endogeneity in this system since citation behavior can be strategic (e.g., this new paper in R.E. Stat), and many a scientific discovery has been waylaid by collusive behavior among scientists (see, for example, the rise and fall of radical mastectomies as detailed in Emperor of All Maladies, previously here). That said, the next time someone tells you there's a legitimate scientific debate over whether anthropogenic climate change is occurring, I think you can safely make a "we are the 98%" joke.


Evidence of a link between migration and malaria

Alan Barreca, Price V. Fishback, and Shawn Kantor 

Abstract: The Agricultural Adjustment Act (AAA) caused a population shift in the United States in the 1930s. Evaluating the effects of the AAA on the incidence of malaria can therefore offer important lessons regarding the broader consequences of demographic changes. Using a quasi-first difference model and a robust set of controls, we find a negative association between AAA expenditures and malaria death rates at the county level. Further, we find the AAA caused relatively low-income groups to migrate from counties with high-risk malaria ecologies. These results suggest that the AAA-induced migration played an important role in the reduction of malaria.


Increasing income increases deforestation in Mexico

Over a year ago, I pointed readers to this paper after seeing it at WCERE and thinking it was important, so I'm happy to hear that its now forthcoming in ReStat.  It is also is also an excellent example of individuals increasing their resource consumption, when they becoming richer, by increasing their trophic level (described two posts ago).  The paper finds that when households receive cash transfers, they consume more meat, which requires more rangeland, which induces additional deforestation.

Jennifer Alix-Garcia, Craig McIntosh, Jarrod R. Welch, Katharine R. E. Sims 

Abstract: We study the consequences of poverty alleviation programs for environmental degradation. We exploit the community-level eligibility discontinuity for a conditional cash transfer program in Mexico to identify the impacts of income increases on deforestation, and use the program’s initial randomized rollout to explore household responses. We find that additional income raises consumption of land-intensive goods and increases deforestation. The observed production response and deforestation increase are larger in communities with poor road infrastructure. This suggests that better access to markets disperses environmental harm and that the full effects of poverty alleviation can be observed only where poor infrastructure localizes them.


Consensus building and norm engineering

The New York Times has a fascinating article on a recent radical decline in the prevalence of female genital cutting / mutilation in Senegal:
Across the continent, an estimated 92 million girls and women have undergone [genital cutting]. But like more than 5,000 other Senegalese villages, Sare Harouna has joined a growing movement to end the practice.
The change has not yet reached Ms. Kande’s new home in her husband’s village, but if elders there pressured her to cut the baby girl she is taking into the marriage, she said, “I would resist them.” Her parents back her up.
“They would never dare do that to my granddaughter, and we would never allow it,” said Ms. Kande’s mother, Marietou Diamank.
The movement to end genital cutting is spreading in Senegal at a quickening pace through the very ties of family and ethnicity that used to entrench it. And a practice once seen as an immutable part of a girl’s life in many ethnic groups and African nations is ebbing, though rarely at the pace or with the organized drive found in Senegal. ...
[H]ere in Senegal, Tostan, a group whose name means “breakthrough” in Wolof, Senegal’s dominant language, has had a major impact with an education program that seeks to build consensus, African-style, on the dangers of the practice, while being careful not to denounce it as barbaric as Western activists have been prone to do.
The movement's success is heavily attributed to its inclusivity and consensus building, and the anecdotal evidence in the article seems to back it up. The fact that Tostan's strategy heavily involves griots, traditional story tellers who are somewhere between musician, MC, and radio personalities, seems particularly intuitive and appealing, a bit like trying to get celebrities and athletes in the US to speak out against smoking.

Along those lines, attributing of the program's success to having tailored itself to "African-style" consensus building seems rather small-minded. There are obviously many ways to get people to change their behavior (taxation, accolades, providing information ...), but abolishing genital mutilation seems to be a classic case of changing social norms, and when you think about it, a social norm is nothing more than a codification of expectations over the everyone's behavior. Changing a social norm involves shifting from one equilibrium state of expectations (everyone knows genital cutting is common and necessary and if my daughter doesn't undergo it she and my family will be judged) to another (everyone knows genital cutting is dangerous and unnecessary and if someone asks my daughter to do it they're crazy) for the entire group of individuals. It is, by definition, establishing a consensus. 

I think we can thus say that Tostan's success (to the extent that the success is Tostan's and not attributable to larger demographic forces) lies less in exploiting some native preference for consensus that "Africans" have than in focusing efforts on small clusters of individuals with correlated norms (villages), and then propagating that norm change through the next-closest set of clusters (neighboring / inter-marrying villages). That Tostan works to convince those individuals in an inoffensive way (try convincing anyone, anywhere, to stop doing something because it's 'barbaric') seems necessary but not sufficient to effect that change. 


Innovation competitions

Jesse and I are working under a deadline, so our posts are suffering. Here are some links that might distract you from our inability to do two things at once.

Create a data visualization for global groundwater trends and have your work shown on the side of a building in Times Square.

A million dollar prize is awarded to a company for designing a more efficient oil skimmer. Video below.

Also, this is just plain amazing (from Jesse).


Trophic level as a measure of economic development?

I will return this this new Nature article in another post, since it brings up a lot of interesting points, but I think this ancillary point was worth highlighting (even though the authors don't make this case): Looking at where humans sit in the food chain might be a useful (or at least interesting) measure of economic development.  In rich countries, land is used to feed animals that we eat.  In poor countries, people eat a higher fraction of crops themselves.  We've known about this phenomenon for a while now, but this map from the paper is striking because of its fully global perspective:

Here we show the fraction of the world’s total cropland that is dedicated to growing food crops (crops that are directly consumed by people) versus all other crop uses, including animal feed, fibre, bioenergy crops and other products. Averaged across the globe, 62% of total crop production (on a mass basis) is allocated to human food, 35% for animal feed (which produces human food indirectly, and less efficiently, as meat and dairy products) and 3% for bioenergy crops, seed, and other industrial products. There are striking disparities between regions that primarily grow crops for human consumption (such as Africa, South Asia, East Asia), and those that mainly produce crops for other uses (such as North America, Europe, Australia).
Copyright: Nature


Valuing clean water in rural Kenya

My big sister spent a year in Malawi working on improving communal water infrastructure.  She came home fed up because, among other things, it seemed like nobody was willing to pay for investments in their own infrastructure (if I recall correctly, the Clinton Foundation was trying to pay for the initial construction, but the communities weren't even willing to pay for the maintenance).  I found this puzzling and wasn't sure I believed it at the time, but I guess I do now since the QJE says so.  My big sister has really good intuition.

[This work suggests how public and private infrastructure can be compliments.  Protection of public water sources isn't as effective (or highly valued, probably) when recontamination of water occurs in the home.]


Abstract: Using a randomized evaluation in Kenya, we measure health impacts of spring protection, an investment that improves source water quality. We also estimate households’ valuation of spring protection and simulate the welfare impacts of alternatives to the current system of common property rights in water, which limits incentives for private investment. Spring infrastructure investments reduce fecal contamination by 66%, but household water quality improves less, due to recontamination. Child diarrhea falls by one quarter. Travel-cost based revealed preference estimates of households’ valuations are much smaller than both stated preference valuations and health planners’ valuations, and are consistent with models in which the demand for health is highly income elastic. We estimate that private property norms would generate little additional investment while imposing large static costs due to above-marginal-cost pricing, private property would function better at higher income levels or under water scarcity, and alternative institutions could yield Pareto improvements.


Guide to the Nobel laureates in economics

The Nobel prize in economics* was awarded to the macroeconomists Thomas J. Sargent and Christopher A. Sims on Monday. Looking around for a bit of detail on their work I came across Tyler Cowen's annual round up of the Nobels over at Marginal Revolution: 

Let’s go back to the Lucas Critique of 1976. Lucas looked at the large econometric models of the 1970s, models that contained hundreds of variables relating economic aggregates like income, consumption, unemployment and so forth. Lucas then asked whether these models could be used to predict the impact of new policies. One could certainly take the regression coefficients from these models and forecast but Lucas argued that such a method was invalid because the regression coefficients themselves would change with new policies.
If you wanted to understand the effects of a new policy you had to go deeper, you had to model the decision rules of individuals based on deep, invariant or “structural” factors, factors such as how people value labor and leisure, that would not change as policy changed and you had to include in your macro model another deep factor, expectations.
The Nobel for Christopher Sims and Thomas Sargent is for work each did in their quite different ways to develop ideas and techniques to address the Lucas Critique.

There are also good profiles of both Sims and Sargent, including Cowen's trademark one sentence summary of the prize's implications (for Sargent: "Most of all, this is a prize about expectations, macroeconomics, and the theory and empirics of policy"; for Sims: "Basically this is a prize in praise of Minnesota macro, fresh water macro of course, and lots of econometrics.").

* or, officially, The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel. Wikipedia has (as usual) a good overview of how the economics prize differs from the rest of the Nobels (something I didn't even know before grad school).


More European worry, this time about science research

Science is Vital delivered a report at the request of the UK parliament regarding the state of scientific careers in the UK.  It's not optimistic or surprising:
Executive Summary 
Science is vital for the UK economy. A healthy scientific career structure, in turn, is crucial to maintain our strong research base, especially in a time of public austerity. Science is Vital, a grassroots campaigning group with the aim of protecting and championing science in the UK, recently conducted a consultation amongst a wide range of scientists in the UK to explore their views on the career structure of the profession. 
Nearly 700 respondents, distributed across the spectrum of the scientific career, submitted written evidence – from students and postdocs to principal investigators, department heads, emeritus professors and Fellows of the Royal Society, representing more than 160 institutions across all four nations of the United Kingdom. We found that the top concern of these scientists was the career instability caused by successive fixed-term contracts and the shortage of permanent research positions. Other problems included issues of pay, mobility, balancing work with having a family or relationship, pressure to assess impact, and the fact that in many cases younger scientists are not allowed to facilitate their careers by applying for their own grants. 
This exercise uncovered the widespread view that the scientific career structure in the UK is not fit for purpose. If the situation is not improved, we risk seriously undermining our research base and, in turn, imperilling the economy. Clearly, increasing funding for science in the next budget would significantly help ease the pressure. In the meantime, however, drawing from our respondents’ ideas, we have proposed a number of solutions that we would like to see discussed among government, scientists, funding bodies and universities, including: 
  • The creation of more permanent research staff positions that are not principal investigators/lab heads
  • More funding earmarked to help bridge the transition from postdoc to independent position
  • More independent fellowships, and the abolition of eligibility criteria that effectively discriminate against older postdocs or those who have followed a non-traditional career path
  • Increased opportunities for postdocs to apply for project grants as the named investigator in their own right
  • The inclusion of early and mid-career researchers in ongoing discussions about the scientific career structure and funding issues
  • Private sector contributions to scientific training
  • Improved career advice for PhD students and postdocs
(h/t to Andy Neal)


Poverty and climate change are the "two most serious issues facing the world" according to Europeans

When Matt Kahn and Matt Kotchen showed that people seemed to worry less about the environment during bad economic times (at least according to their Google searches) some people got worried that during the current economic crisis, global environmental issues would take a back seat.  But a recent report by Eurobarometer suggests that European concern about anthropogenic climate change continues to climb, in spite of the current economic situation. The Guardian reports
The Eurobarometer poll suggests that the majority of the public in the European Union consider global warming to be one of the world's most serious problems, with one-fifth saying it is the single most serious problem. Overall, respondents said climate change was the second most serious issue facing the world, after poverty.


More empirical work needed on climate impacts and adaptation

I've felt the same way for some time, but it's nice that someone decided to look at this systematically.  (Similar conclusions were reached by Aldy et al (JEL, 2010).)

Modeling Climate Change Adaptation: Challenges, Recent Developments and Future Directions
Karen Fisher-Vanden, Ian Sue Wing, Elisa Lanzi, David Popp

Abstract: This paper offers a critical review of modeling practice in the field of integrated assessment of climate change and ways forward.  Past efforts in integrated assessment have concentrated on developing baseline trajectories of emissions and mitigation scenario analyses.  A key missing component in IAMs is the representation of climate impacts and adaptation responses.  Through the examination of conceptual, theoretical and empirical frameworks for the analysis of climate impacts and adaptation, we identify five characteristics of an ideal IAM: regional and sectoral detail for impacts and adaptation strategies; distinct representation of the three types of adaptation—adaptation through market adjustments, protective/defensive expenditures, and adaptive/coping expenditures; intertemporal decision making under uncertainty; induced innovation in adaptation-related technologies; and  connection with empirical work on impacts and adaptation.  Our review of existing IAMs finds that most models are severely lacking in most of these modeling features.

(h/t Daiju)


Good advice

S. Jobs (1955-2011) finished changing the world today.

Energy and temperature are substitutes in the production of health

This week in AEJ Applied:

Climate Change, Mortality, and Adaptation: Evidence from Annual Fluctuations in Weather in the US 
Olivier Deschênes and Michael Greenstone

Abstract: Using random year-to-year variation in temperature, we document the relationship between daily temperatures and annual mortality rates and daily temperatures and annual residential energy consumption. Both relationships exhibit nonlinearities, with significant increases at the extremes of the temperature distribution. The application of these results to "business as usual" climate predictions indicates that by the end of the century climate change will lead to increases of 3 percent in the age-adjusted mortality rate and 11 percent in annual residential energy consumption. These estimates likely overstate the long-run costs, because climate change will unfold gradually allowing individuals to engage in a wider set of adaptations.

More on temperature's substitutes/compliments here and here.

(h/t Michael O)


Did the global climate cause dark ages and golden ages?

Yesterday in PNAS:

The causality analysis of climate change and large-scale human crisis

David D. Zhang, Harry F. Lee, Cong Wang, Baosheng Li, Qing Pei, Jane Zhang, and Yulun An

Abstract: Recent studies have shown strong temporal correlations between past climate changes and societal crises. However, the specific causal mechanisms underlying this relation have not been addressed. We explored quantitative responses of 14 fine-grained agro-ecological, socioeconomic, and demographic variables to climate fluctuations from A.D. 1500–1800 in Europe. Results show that cooling from A.D. 1560–1660 caused successive agro-ecological, socioeconomic, and demographic catastrophes, leading to the General Crisis of the Seventeenth Century. We identified a set of causal linkages between climate change and human crisis. Using temperature data and climate-driven economic variables, we simulated the alternation of defined “golden” and “dark” ages in Europe and the Northern Hemisphere during the past millennium. Our findings indicate that climate change was the ultimate cause, and climate-driven economic downturn was the direct cause, of large-scale human crises in preindustrial Europe and the Northern Hemisphere.

Comment I gave to a journalist:

Zhang et al. have done an impressive job of collecting, organizing and making sense of many pieces of data.  If links from the global climate to food supply to conflict were underlying historical periods of unrest, this will certainly change how we understand historical developments in Europe.  The work by Zhang et al. is particularly interesting because they have tried to examine the detailed pathways that link the global climate to social upheaval.  Their finding that agricultural productivity, agricultural wages and food prices all might have contributed to conflict agrees with a number of leading hypotheses in the field, and they are certainly consistent with observations made in other studies.

It is difficult to know exactly how much these findings can tell us about the modern world, since many things have changed since 1800.  However, it is worth noting that per capita incomes in Europe at 1800 were similar to those we observe in many modern low income countries, such as Bangladesh, Haiti, Nepal and much of Sub-Saharan Africa.  So if poverty is a key factor in the link between the global climate and conflict, the global population in the 21st century is still not wealthy enough that we can consider ourselves "out of the woods."

[Related here, here, here, here, here, here, here and here]


I'm unhappy because (a) I'm poor, (b) the S&P tanked, (c) it's 3:00 PM, (d) all of the above

Following up on our post on income vs happiness, there's more research coming out this week: time vs. happiness (Science) and stock market vs. happiness (NBER).

Scott A. Golder & Michael W. Macy

Abstract: We identified individual-level diurnal and seasonal mood rhythms in cultures across the globe, using data from millions of public Twitter messages. We found that individuals awaken in a good mood that deteriorates as the day progresses—which is consistent with the effects of sleep and circadian rhythm—and that seasonal change in baseline positive affect varies with change in daylength. People are happier on weekends, but the morning peak in positive affect is delayed by 2 hours, which suggests that people awaken later on weekends.

Hourly changes in individual affect broken down by day of the week (top, PA; bottom, NA). Each series shows mean affect (black lines) and 95% confidence interval (colored regions). Credit: Science

The Financial Crisis and the Well-Being of Americans
Angus S. Deaton

Abstract: The Great Recession was associated with large changes in income, wealth, and unemployment, changes that affected many lives. Since January 2008, the Gallup Organization has been collecting daily data on 1,000 Americans each day, with a range of self-reported well-being (SWB) questions. I use these data to examine how the recession affected the emotional and evaluative lives of the population, as well as of subgroups within it. In the fall of 2008, around the time of the collapse of Lehman Brothers, and lasting into the spring of 2009, at the bottom of the stock market, Americans reported sharp declines in their life evaluation, sharp increases in worry and stress, and declines in positive affect. By the end of 2010, in spite of continuing high unemployment, these measures had largely recovered, though worry remained higher and life evaluation lower than in January 2008. The SWB measures do a much better job of monitoring short-run levels of anxiety as the crisis unfolded than they do of reflecting the evolution of the economy over a year or two. Even large macroeconomic shocks to income and unemployment can be expected to produce only small and hard to detect effects on SWB measures. SWB, particularly evaluation of life as a whole, is sensitive to question order effects. Asking political questions before the life evaluation question reduces reported life evaluation by an amount that dwarfs the effects of even the worst of the crisis; these order effects persist deep into the interview, and condition the reporting of hedonic experience and of satisfaction with standard of living. Methods for controlling these effects need to be developed and tested if national measures are to be comparable over space and time.

"ladder" is a measure of positive feelings about one's life evaluation.