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Marshall Burke and fellow researchers study productivity in smallholder farms to understand variation across the adbundant but understudied firms. They use a novel framework, satellite data, and machine learning to understand such variation, and they find that output measurement error contributes significantly to this discrepancy in productivity.

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Working Papers
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National Bureau of Economic Research
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Marshall Burke
Casey C. Maue
Kyle J. Emerick
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Researchers including David Lobell analyze how human-caused climate change has impacted a water deficit in Southern Africa and might contribute to a rising food security crisis in the region.

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Global Change Biology
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David Lobell
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The advent of multiple satellite systems capable of resolving smallholder agricultural plots raises possibilities for significant advances in measuring and understanding agricultural productivity in smallholder systems. However, since only imperfect yield data are typically available for model training and validation, assessing the accuracy of satellite-based estimates remains a central challenge. Leveraging a survey experiment in Mali, this study uses plot-level sorghum yield estimates, based on farmer reporting and crop cutting, to construct and evaluate estimates from three satellite-based sensors. Consistent with prior work, the analysis indicates low correlation between the ground-based yield measures (r = 0.33). Satellite greenness, as measured by the growing season peak value of the green chlorophyll vegetation index from Sentinel-2, correlates much more strongly with crop cut (r = 0.48) than with self-reported (r = 0.22) yields. Given the inevitable limitations of ground-based measures, the paper reports the results from the regressions of self-reported, crop cut, and (crop cut-calibrated) satellite sorghum yields. The regression covariates explain more than twice as much variation in calibrated satellite yields (R2 = 0.25) compared to self-reported or crop cut yields, suggesting that a satellite-based approach anchored in crop cuts can be used to track sorghum yields as well or perhaps better than traditional measures. Finally, the paper gauges the sensitivity of yield predictions to the use of Sentinel-2 versus higher-resolution imagery from Planetscope and DigitalGlobe. All three sensors exhibit similar performance, suggesting little gains from finer resolutions in this system.

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Remote Sensing MDPI
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David Lobell
Stefania Di Tommaso
Marshall Burke
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David Beasley
Please join us for a conversation with United Nations World Food Programme Executive Director David Beasley, who will discuss "Challenges of 21st Century Humanitarian Response." The conversation will be moderated by his predecessor at the agency, Ertharin Cousin, a visiting fellow at the Center on Food Security and the Environment.

R.S.V.P.

As Executive Director of the World Foods Programme (WFP), Mr. Beasley serves at the level of Under-Secretary-General of the United Nations and is a member of the organization's Senior Management Group under the leadership of Secretary-General António Guterres. At WFP, he is putting to use four decades of leadership and communications skills to mobilize more financial support and public awareness for the global fight against hunger. Under his leadership, WFP kept four countries from slipping into famine in 2017 and is moving beyond emergency food assistance, to advance longer term development that brings peace and stability to troubled regions. Before coming to WFP in April 2017, Beasley spent a decade working with high-profile leaders and on-the-ground programme managers in more than 100 countries, directing projects designed to foster peace, reconciliation and economic progress.

David Beasley was elected at the age of 21 to the South Carolina House of Representatives (1979-1992) and as Governor of South Carolina (1995-1999), one of the youngest in the state’s history.  He received a Profile in Courage Award in 2003 from the John F. Kennedy Library Foundation and is a 1999 Fellow of the Institute of Politics at Harvard University’s Kennedy School of Government. Born in 1957, he attended Clemson University and holds a B.A. from the University of South Carolina, as well as a J.D. from the University of South Carolina School of Law.

The Conversation with David Beasley is co-sponsored by Stanford’s Freeman Spogli Institute for International Studies; the Center on Food Security and the Environment and the Annenberg Foundation Trust at Sunnylands.

 The lecture will be held at the David and Joan Traitel Building, 435 Lasuen Mall, Stanford University. For more information about the event, contact Sonal Singh at sonals@stanford.edu.

About the Wesson Lecture

The Wesson Lectureship was established at Stanford by the Freeman Spogli Institute for International Studies in 1988. It provides support for a public address at the university by a prominent scholar or practicing professional in the field of international relations. The series is made possible by a gift from the late Robert G. Wesson, a scholar of international affairs, prolific author, and senior research fellow at the Hoover Institution.

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Our Report draws attention to a complex but understudied issue: How will climate warming alter losses of major food crops to insect pests? Because empirical evidence on plant-insect-climate interactions is scarce and geographically localized, we developed a physiologically based model that incorporates strong and well-established effects of temperature on metabolic rates and on population growth rates. We acknowledged that other factors are involved, but the ones we analyzed are general, robust, and global (13).

Parmesan and colleagues argue that our model is overly simplistic and that any general model is premature. They are concerned that our model does not incorporate admittedly idiosyncratic and geographically localized aspects of plant-insect interactions. Some local effects, such as evidence that warmer winters will harm some insects but not others, were in fact evaluated in our sensitivity analyses and shown to be minor (see the Report's Supplementary Materials). Other phenomena, such as plant defenses that benefit some insects and threaten others, are relevant but are neither global nor directional. Furthermore, because Parmesan et al. present no evidence that such idiosyncratic and localized interactions will outweigh the cardinal and universally strong impacts of temperature on populations and on metabolic rates (13), their conclusion is subjective.

We agree with Parmesan and colleagues that the question of future crop losses is important and needs further study, that targeted experimental data are needed (as we wrote in our Report), and that our estimates are likely to be conservative (as we concluded, but for reasons different from theirs). However, we strongly disagree with their recommendation to give research priority to gathering localized experimental data. That strategy will only induce a substantial time lag before future crop losses can be addressed.

We draw a lesson from models projecting future climates. Those models lack the “complexity and idiosyncratic nature” of many climate processes, but by building from a few robust principles, they successfully capture the essence of climate patterns and trends (4). Similarly, we hold that the most expeditious and effective way to anticipate crop losses is to develop well-evidenced ecological models and use them to help guide targeted experimental approaches, which can subsequently guide revised ecological models. Experiments and models should be complementary, not sequential.

 
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Science
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Curtis A. Deutsch, Joshua J. Tewksbury, Michelle Tigchelaar, David S. Battisti, Scott C. Merrill, Raymond B. Huey
Rosamond L. Naylor
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Reconciling higher freshwater demands with finite freshwater resources remains one of the great policy dilemmas. Given that crop irrigation constitutes 70% of global water extractions, which contributes up to 40% of globally available calories (1), governments often support increases in irrigation efficiency (IE), promoting advanced technologies to improve the “crop per drop.” This provides private benefits to irrigators and is justified, in part, on the premise that increases in IE “save” water for reallocation to other sectors, including cities and the environment. Yet substantial scientific evidence (2) has long shown that increased IE rarely delivers the presumed public-good benefits of increased water availability. Decision-makers typically have not known or understood the importance of basin-scale water accounting or of the behavioral responses of irrigators to subsidies to increase IE. We show that to mitigate global water scarcity, increases in IE must be accompanied by robust water accounting and measurements, a cap on extractions, an assessment of uncertainties, the valuation of trade-offs, and a better understanding of the incentives and behavior of irrigators.

 
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Science
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Quentin Grafton
J. Williams, C. J. Perry, F. Molle, C. Ringler, P. Steduto, B. Udall, S. A. Wheeler, Y. Wang, D. Garrick, R. G. Allen
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Crop responses to climate warming suggest that yields will decrease as growing-season temperatures increase. Deutsch et al. show that this effect may be exacerbated by insect pests (see the Perspective by Riegler). Insects already consume 5 to 20% of major grain crops. The authors' models show that for the three most important grain crops—wheat, rice, and maize—yield lost to insects will increase by 10 to 25% per degree Celsius of warming, hitting hardest in the temperate zone. These findings provide an estimate of further potential climate impacts on global food supply and a benchmark for future regional and field-specific studies of crop-pest-climate interactions.

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Science
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Curtis A. Deutsch, Joshua J. Tewksbury, Michelle Tigchelaar, David S. Battisti, Scott C. Merrill, Raymond B. Huey
Rosamond L. Naylor
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The extent to which armed conflicts—events such as civil wars, rebellions, and interstate conflicts—are an important driver of child mortality is unclear. While young children are rarely direct combatants in armed conflict, the violent and destructive nature of such events might harm vulnerable populations residing in conflict-affected areas. A 2017 review estimated that deaths of individuals not involved in combat outnumber deaths of those directly involved in the conflict, often more than five to one. At the same time, national child mortality continues to decline, even in highly conflict-prone countries such as Angola or the Democratic Republic of the Congo. With few notable exceptions, such as the Rwandan genocide or the ongoing Syrian Civil War, conflicts have not had clear reflections in national child mortality trends.

 

 The Global Burden of Disease study estimated that, since 1994, conflicts caused less than 0·4% of deaths of children younger than 5 years in Africa, raising questions about the role of conflict in the global epidemiology of child mortality. The extent to which conflict matters to child mortality therefore remains largely unmeasured beyond specific conflicts. In Africa, conflict-prone countries also have some of the highest child mortality, but this might be a reflection of generalised underdevelopment resulting in proneness to conflict as well as high child mortality, rather than a direct relationship. In this analysis we aimed to shed new light on the effects of armed conflict on child mortality in Africa. We established the effects on child mortality of armed conflict in whom conflict-related deaths are not the result of active involvement in conflict, but of other consequences of conflict. We examined the duration of lingering conflict effects, and the geographical breadth of the observed effects, using geospatially explicit information on conflict location and number of conflict-related casualties. We then used our findings to estimate the burden of armed conflict on children younger than 5 years in Africa.

 

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The Lancet
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Zachary Wagner
Sam Heft-Neal
Zulfiqar A Bhutta,Robert E Black
Marshall Burke
Eran Bendavid
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More children die from the indirect impact of armed conflict in Africa than those killed in the crossfire and on the battlefields, according to a new study by Stanford researchers. 

The study is the first comprehensive analysis of the large and lingering effects of armed conflicts — civil wars, rebellions and interstate conflicts — on the health of noncombatants.

The numbers are sobering: 3.1 to 3.5 million infants born within 30 miles of armed conflict died from indirect consequences of battle zones between 1995 and 2005. That number jumps to 5 million deaths of children under 5 in those same conflict zones.

“The indirect effects on children are so much greater than the direct deaths from conflict,” said Stanford Health Policy's Eran Bendavid, senior author of the study published today in The Lancet.

The authors also found evidence of increased mortality risk from armed conflict as far as 60 miles away and for eight years after conflicts. Being born in the same year as a nearby armed conflict is riskiest for young infants, the authors found, with the lingering effects raising the risk of death for infants by over 30 percent.

On the entire continent, the authors wrote, the number of infant deaths related to conflict from 1995 to 2015 were more than three times the number of direct deaths from armed conflict. Further, they demonstrated a strong and stable increase of 7.7 percent in the risk of dying before age 1 among babies born within 30 miles of an armed conflict.

The authors recognize it is not surprising that African children are vulnerable to nearby armed conflict. But they show that this burden is substantially higher than previously indicated. 

“We wanted to understands the effects of war and conflict, and discovered that this was surprisingly poorly understood,” said Bendavid, an associate professor of medicine at Stanford Medicine.  “The most authoritative source, the Global Burden of Disease, only counts the direct deaths from conflict, and those estimates suggest that conflicts are a minuscule cause of death.”

Paul Wise, a professor of pediatrics at Stanford Medicine and a senior fellow at the Freeman Spogli Institute for International Studies, has long argued that lack of health care, vaccines, food, water and shelter kills more civilians than combatants from bombs and bullets. 

This study has now put data behind the theory when it comes to children.

“We hope to redefine what conflict means for civilian populations by showing how enduring and how far-reaching the destructive effects of conflict have on child health,” said Bendavid, an infectious disease physician whose co-authors include Marshall Burke, PhD, an assistant professor of earth systems science and fellow at the Center on Food Security and the Environment.

“Lack of access to key health services or to adequate nutrition are the standard explanations for stubbornly high infant mortality rates in parts of Africa,” said Burke. “But our data suggest that conflict can itself be a key driver of these outcomes, affecting health services and nutritional outcomes hundreds of kilometers away and for nearly a decade after the conflict event”. 

The results suggest efforts to reduce conflict could lead to large health benefits for children.

The Data

The authors matched data on 15,441 armed-conflict events with data on 1.99 million births and subsequent child survival across 35 African countries. Their primary conflict data came from the Uppsala Conflict Data Program Georeferenced Events Dataset, which includes detailed information about the time, location, type and intensity of conflict events from 1946 to 2016. 

The researchers also used all available data from the Demographic and Health Surveys conducted in 35 African countries from 1995 to 2015 as the primary data sources on child mortality in their analysis.

The data, they said, shows that the indirect toll of armed conflict among children is three-to-five times greater than the estimated number of direct casualties in conflict. The indirect toll is likely even higher when considering the effects on women and other vulnerable populations.

Zachary Wagner, a health economist at RAND Corporation and first author of the study, said he knows few are surprised that conflict is bad for child health.

“However, this work shows that the relationship between conflict and child mortality is stronger than previously thought and children in conflict zones remain at risk for many years after the conflict ends.” 

He notes that nearly 7 percent of child deaths in Africa are related to conflict and reiterated the grim fact that child deaths greatly outnumber direct combatant deaths.

“We hope our findings lead to enhanced efforts to reach children in conflict zones with humanitarian interventions,” Wagner said. “But we need more research that studies the reasons for why children in conflict zones have worse outcomes in order to effectively intervene.” 

Another author, Sam Heft-Neal, PhD, is a research fellow at the Center for Food Security and the Environment and in the Department of Earth Systems Science. He, Burke and Bendavid have been working together to identify the impacts of extreme climate events on infant mortality in Africa.

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Áine Josephine Tyrrell
Nicole Feldman
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The Freeman Spogli Institute for International Studies (FSI) at Stanford University is pleased to announce that former U.S. Ambassador and World Food Programme (WFP) Executive Director Ertharin Cousin will return for a second year at Stanford. Cousin will serve as the Frank E. and Arthur W. Payne Distinguished Lecturer at FSI and Distinguished Fellow at the Center on Food Security and the Environment and the Center on Democracy, Development and the Rule of Law.

Cousin brings over 30 years of experience addressing hunger and food security strategies on both a national and international scale. As U.S. Ambassador to the United Nations Agencies for Food and Agriculture, she focused on advocating for longer-term solutions to food insecurity and hunger, and at WFP she addressed the challenges of food insecurity in conflict situations.

We caught up with Cousin to ask about her plans for this upcoming school year.

If you had to pick out one thing that most concerns you in the realm of food security, what would it be?

Water access, particularly in terms of smallholder farmer centered irrigation and water management. The development community spent much of the past 10 years working to improve farmers’ access to the right seeds and tools – recognizing the need to increase the quality and quantity of their yields. A significant amount of work has also been performed related to improving private sector investment and to the development of markets including access for smallholder farmers.

Today there are approximately 500 million smallholder farmers in the world. The most vulnerable live and work in places where climate change creates ever more erratic rainy seasons. Particularly, in sub-Saharan Africa where 97 percent of all agriculture remains rain-fed. Too often the short rains don’t come, and the long rains produce insufficient precipitation. Inadequate policy management of diminishing water resources represents a significant problem which we must overcome to make agriculture productive and sustainable for the most vulnerable.

And what work have you been doing to address this issue?

I am working on a number of policy research and development projects. For example, I am co-chairing the Chicago Council on Global Affairs (CCGA) 2019 Global Food Security Symposium’s report exploring the linkages between water management and food security particularly as it relates to nutrition security. The report release will occur March 21, 2019 at the CCGA Food Security Symposium.

Over the past year, you also have been working on a project to encourage the private sector to create sustainable food systems. How is that going?

My work identifying and addressing policy-related challenges impacting private sector partnership and investment in global food system solutions continues. Globally, there is growing recognition that we cannot fix the broken global food system if we do not work to create collaborative efforts between public and private sector, academia, government, non-profits and larger society.

Governments, particularly those in developing countries, often lack both the financial resources and technical capacity required to perform the work and the investment necessary to fix our global food system. Governments and civil society must include private sector as an equal and desired partner. Government policies at the global, state and local level should support and encourage private sector participation.

Using my role here at Stanford as a platform to broker research and information both to private sector as well as to government, has proven quite successful over the past year. In very simple terms, helping global governments understand generating profit does not make the private sector a bad partner.

What successes have you had so far?

I was just in Amsterdam to meet with Royal DSM, a nutrition products manufacturer, with whom I developed a relationship during my tenure at the World Food Programme. In Kigali in Rwanda, DSM and several other partners - including the national government - have developed and are now operating the Africa Improved Foods company, the first European-type baby food manufacturing facility. European-type baby food differs from American products in terms of their lack of sweeteners and conservative use of food preservatives, lack of detectable pesticides (due to farming practices), and their stage-approach: they produce different products for the various stages of baby growth (from birth to 4 years) that cater to the specific nutritional needs of the child. Several farming cooperatives, representing approximately 10,000 Rwandan small farmers, form the sole supply chain for this baby food factory.

WFP serves as a catalyst market for the plant, purchasing the supplemental nutrition product distributed through the region’s targeted nutrition improvement program. The sustainability of the factory is directly related to the partners ability to grow (in addition to WFP) an institutional and a commercial consumer market for this easy-access, nutrient-rich food that is specifically made for children. I am assisting DSM and the government of Rwanda by helping to identify the policy changes required to ensure the sustainability of this public-private partnership. As a proof-of-concept, the success of AIF, will result in new public-private development opportunities. This initiative offers a case study demonstrating how collaboration between the private sector and government actually provides positive benefits for both farmers and nutritious food for consumers.

Why Stanford? How has being here helped your work?

Serving here at Stanford represents my first opportunity to work in academia on a full-time basis. I am a lawyer with over 30 years of experience of working on complicated domestic and global humanitarian and development issues; particularly, hunger related issues. I believe my experience adds value to any academic community. But in many institutions, the value of experience is not readily embraced, particularly because I don't have a PhD and haven’t spent 20 years in a classroom. At Stanford, I discovered collegial faculty, brilliant students and a recognition as well as a respect for my experience-based knowledge. I have received a welcoming response across the campus, collaborating with the law school, colleagues in the medical school, earth system sciences and the business school. The only limit to my participation and partnership with the amazing academic leaders here at Stanford has been time. I am quite looking forward to the opportunities for engagement provided by my additional time on campus.

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The Payne Distinguished Lectureship is awarded to scholars with international reputations as leaders, with an emphasis on visionary thinking, practical problem solving, and the capacity to clearly articulate an important perspective on the global political and social situation. Past Payne Lecturers include Bill Gates, Nobel Laureate Mohamed El Baradei, UNAIDS Executive Director Peter Piot, and novelist Ian McEwan.

The Center on Food Security and the Environment (FSE) addresses critical global issues of hunger, poverty and environmental degradation and is a joint effort of the Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment.

The Center on Democracy, Development and the Rule of Law is an interdisciplinary center for research on development in all of its dimensions:  political, economic, social and legal, and the ways in which these different dimensions interact with one another.

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