IFPRI Journal Articles

Permanent URI for this collectionhttps://hdl.handle.net/10568/128834

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Dataset on the patterns of livelihood diversification in farming systems of the Eastern Gangetic Plains of South Asia
(Journal Article, 2025) Jackson, Tamara M.; Nandi, Ravi; Jannat, Arifa; Ghosh, Arunava; Hajra, Dilip Kumar; Mitra, Biplab; Rashid, Md Mamunur; Bista, Sagar; Chaudhary, Anjana; Timsina, Pragya; Karki, Emma; Thapa, Kali Rattan; Rana, Gunjan; Kishore, Avinash
The Eastern Gangetic Plains (EGP) region, characterized by smallholder-dominated farming, is experiencing rapid socio-economic and environmental changes. To enhance resilience, income stability, and food security, smallholders are increasingly diversifying their livelihoods away from traditional agriculture. However, the patterns and drivers of this diversification remain poorly understood. This study, utilizing data from the Rupantar project, aims to elucidate these patterns, identify key drivers, and assess the impacts on productivity, profitability, nutrition, and inclusion. A mixed-methods approach was employed, including a baseline survey of 1,400 households across India, Nepal, and Bangladesh and analysis using the Simpson's Index of Diversity (SID). Fractional regression models revealed moderate diversification levels across the EGP with significant geographical and contextual variability. Key drivers included access to resources, gender, education, market access, and institutional support, with differences observed across countries and diversification types. Factors such as non-ownership of irrigation pumps, female household headship, and engagement in off-farm activities were significant predictors of higher diversification. The study found that diversification can enhance income security, nutritional outcomes, and environmental sustainability, although impacts vary by diversification type.
Menarche and pubertal progression: A cross-sectional analysis of timing and influencing factors in North-Eastern Ghana
(Journal Article, 2025) Alatiah, Gabriel Ajediwe; Azupogo, Fusta; Atosona, Ambrose; Vuvor, Frederick; Steiner-Asiedu, Matilda; Brouwer, Inge D.
Menarche and pubertal onset vary across populations but understanding age-at-menarche (AAM) and pubertal growth tempo is limited in low-income settings. Identifying factors influencing pubertal development is vital for creating targeted health and education programmes supporting adolescent girls’ well-being. Baseline data (n = 1045) from the Ten2Twenty-Ghana study were analysed to examine menarche attainment, pubertal development, AAM, and the associated factors among girls aged 10-17 years in the Mion district, Ghana. The data collection methods included anthropometry, body composition, haemoglobin status, a qualitative 24-hour dietary recall, a food frequency questionnaire, and a pubertal development score (PDS). Binary logistic and linear regression analyses were used to model odds ratios for menarche attainment and regression coefficients for AAM and PDS. About 19.9% of the girls had experienced menarche, with a mean AAM of 13.4 ± 1.5 years. Among post-menarche girls (n = 205/1045), 12.2% and 15.1% experienced early (AAM < 12 years) and late menarche (AAM < 15 years), respectively. The mean PDS was 1.8 ± 0.7 out of 4. Among the adolescent girls, 36.2% were prepubertal, 17.0% early –pubertal, 18.6% mid-pubertal, 27.9% late pubertal, and less than 1% were in the post-pubertal stage. An increase in fat mass (FM), fat-free mass (FFM), height-for-age-z-score (HAZ), and body mass index-for-age-z-score (BAZ) was observed with puberty progression, but a steep decline in HAZ was noticed for girls in late puberty, increasing again post-puberty. Being older (adjusted odds ratio (AOR) = 2.06, 95% C.I.: 1.83, 2.31), stunted (AOR= 0.20, 95% C.I.: 0.10, 0.40), thin (AOR = 0.30, 95% C.I.: 0.11, 0.80), and overweight/obese (AOR = 7.29, 95% C.I.: 2.60, 20.43) were the significant predictors of menarche attainment. Being older (β = 0.39, P < 0.0001), stunted (β= -0.92, P = 0.01), thin (β = 1.25, P = 0.01), and having a literate mother (β = -0.72, P = 0.03) were significantly associated with AMM. A higher HAZ, FM, FFM, age, and Konkomba ethnicity were positively associated with higher PDS. This study highlights the complexity of factors influencing menarche and pubertal development. These insights are essential for developing targeted health and educational programmes that address nutritional and socio-demographic disparities to promote adolescent girls’ well-being and healthy pubertal development.
Estimating the direct and indirect effects of improved seed adoption on yields: Evidence from DNA-fingerprinting, crop cuts, and self-reporting in Ethiopia
(Journal Article, 2025-05) Jovanovic, Nina; Ricker-Gilbert, Jacob
Farmers' adoption of improved crop varieties could increase yields in low-income countries. However, the presence of measurement error in household surveys poses a challenge to estimating true returns. Using the 2018/19 Ethiopia Socio-economic Survey, we analyze the impacts of how three sources of measurement error: misperceptions of seed varieties, land area, and quantities harvested affect maize yields and input use. These data include DNA-fingerprinting of seed, GPS plot size information, and crop cuts that we compare to farmers’ self-reported estimates of these measures. Results indicate that the measurement error in self-reported seed variety adoption, especially from farmers who did not know they were using improved maize varieties, attenuates their estimated yield gains by 25 percentage points on average. The enhanced genetics of improved seed varieties accounts for a 41-percentage point yield increase over non-improved varieties, and increased input use accounts for a 30-percentage point gain for improved varieties on average. JEL classification: D13, O13, N57, Q12, Q16
Dietary intake and micronutrient adequacy among adults in rural Sri Lanka: Findings from a cross-sectional baseline survey
(Journal Article, 2025) Joyce, Caroline A.; Caswell, Bess L.; Gelli, Aulo; Hess, Sonja Y.; Sitisekara, Hasara; Stewart, Christine P.; Tan, Xiuping; Xiuping, Renuka; Peiris, Kalana; Silva, Renuka; Olney, Deanna K.
Objective To characterize food group consumption, assess the contribution of food groups to energy and micronutrient intake, and estimate usual nutrient intake among adults in rural Sri Lanka. Design A baseline survey (Dec 2020–Feb 2021) was conducted as part of an agriculture-based, nutrition-sensitive resilience program evaluation. Dietary intake was assessed using telephone-based 24-hour recalls (n=1283), with repeat recalls from 769 participants. Mean daily intake of food groups and their contribution to energy and nutrient intakes were calculated. The National Cancer Institute method was used to estimate usual intakes and the prevalence of adequate micronutrient intake (PAI). Differences by sex, district, and wealth were assessed using t-tests and ANOVA. Setting Forty-five rural villages throughout Sri Lanka. Participants Men and women from households in the program evaluation study area. Results On average, grains and coconut milk provided 56% and 12% of energy, respectively. Rice, fish, dairy, and pulses were the primary sources of micronutrients. Participants consumed 118±117g vegetables and 71±243g fruit per day. PAI was <25% for calcium; zinc; niacin; folate; and vitamins B6, B12, and C, reflecting low consumption of animal-source foods (ASF; 80 g/day), whole grains, fruits, and vegetables (F&V). Significant differences in food group consumption by sociodemographic subgroup were observed among districts and wealth quintiles. Conclusions We observed high consumption of rice and coconut milk and low prevalence of micronutrient adequacy. We recommend increasing ASF, whole grain, and F&V consumption to close nutrient gaps, as well as research to identify effective solutions to increase micronutrient intake.
Confidence and information usage: Evidence from soil testing in India
(Journal Article, 2025) Gars, Jared; Fishman, Ram; Kishore, Avinash; Rothler, Yoav; Ward, Patrick S.
Informational barriers are often considered to be a major constraint to the adoption of improved farming practices, inputs, and technologies by smallholder farmers. In the Indian context, it is widely believed that farmers misapply chemical fertilizers because they lack scientific information on soil conditions and corresponding fertilizer recommendations, thus resulting in imbalanced and potentially detrimental fertilizer application. Policymakers are frequently interested in providing farmers with various streams of information to overcome these informational barriers to optimize farming activities. However, such informational interventions frequently fail either because generic recommendations may be ill-suited for decision makers in highly heterogeneous agricultural environments or because farmers' beliefs may be so entrenched as to make them unresponsive to new information. We implemented a field experiment in Bihar, India to test whether plot-specific fertilizer recommendations affect farmers' fertilizer use. We find little evidence for sizable impacts on fertilizer use in general, though impacts are more apparent for low cost or costless recommendations such as increasing the use of highly subsidized fertilizers or shifting the timing of application. Despite modest evidence of such effects, even those fall short of their potential magnitude. We show that treated farmers who are less confident in their subjective beliefs about optimal fertilizer application rates (i.e., with more disperse priors) are more responsive to the recommendations and have a higher ex ante willingness to pay for soil testing. These results suggest that heterogeneity in beliefs may constrain the overall effectiveness of information provision, even when the information is tailored to individual farms. JEL Classification: D83, O13
Short-term and long-term effects of cash for work: Evidence from a randomized controlled trial in Tunisia
(Journal Article, 2025) Leight, Jessica; Mvukiyehe, Eric
JEL Classification: O12, O15
A missing link: The interdependence between sugar-sweetened beverage and cigarette consumption from China
(Journal Article, 2025-01) Liu, Lu; Chen, Kevin Z.
Sugar-sweetened beverages (SSBs) and cigarettes are addictive substances and addictive substances are often related in consumption with each other. However, the potential interdependence between SSB and cigarette consumption has not been explored in the literature. As SSB and cigarette consumption have posed a great threat to individual health, the knowledge of such interdependence is critical for policymakers to design and coordinate government interventions. We thus employed Heckman sample selection model and simultaneous equation model to identify and validate the interdependence between SSB and cigarette consumption across subgroups exhibiting different smoking behaviors with individual-level data from the China Health and Nutrition Survey (CHNS) during the period from 2004 to 2011. We find that SSBs and cigarettes are complements in that individuals who ever smoked are more likely to consume SSBs frequently with higher level of SSB intake eventually and SSB intake of current smokers increases along with the amount of cigarettes smoked. SSBs and cigarettes are also substitutes in that former smokers are more likely to consume SSBs compared with current smokers. The complementary relation observed among current smokers implies that government interventions targeting one of the two goods may yield a double dividend effect on health whereas the substitutable relation displayed by former smokers suggests that the health effect of interventions designed to reduce the consumption of one good may be tempered by an elevated demand for the other.
Teuere Versäumnisse
(Journal Article, 2008-06) von Braun, Joachim
Die Preise für Nahrungsmittel steigen. Das trifft vor allem Arme in den Entwicklungsländern hart. Dort wurde lange zu wenig in die Landwirtschaft investiert, so dass Produktionssteigerungen kurzfristig kaum möglich sind. Um die Krise zu meistern, sind Soforthilfe, Investitionen in eine nachhaltige Landwirtschaft, sozialpolitische Maßnahmen sowie Korrekturen in der Handelspolitik erforderlich.
El aumento mundial en el precio de los alimentos: ¿cómo enfrentar el problema?
(Journal Article, 2008) von Braun, Joachim
The effect of prenatal balanced energy and protein supplementation on gestational weight gain: An individual participant data meta-analysis in low- and middle-income countries
(Journal Article, 2025) Wang, Dongqing; Partap, Uttara; Liu, Enju; Costa, Janaína Calu; Cliffer, Ilana R.; Wang, Molin; Nookala, Sudeer Kumar; Subramoney, Vishak; Briggs, Brittany; Ahmed, Imran; Argaw, Alemayehu; Ariff, Shabina; Bhandari, Nita; Chowdhury, Ranadip; Erchick, Daniel; García-Guerra, Armando; Ghaffarpour, Masoumah; Hanley-Cook, Giles; Huybregts, Lieven; Jehan, Fyezah; Kaseb, Fatemeh; Krebs, Nancy F.; Lachat, Carl; Lama, Tsering Pema; Manandhar, Dharma S.; McClure, Elizabeth M.; Moore, Sophie E.; Muhammad, Ameer; Neufeld, Lynnette M.; Prentice, Andrew M.; Quezada-Sánchez, Amado D.; Roberfroid, Dominique; Saville, Naomi M.; Shafiq, Yasir; Shrestha, Bhim P.; Sonko, Bakary; Soofi, Sajid; Taneja, Sunita; Tielsch, James M.; Toe, Laéticia Céline; Valaei, Naser; Fawzi, Wafaie W.
Background Understanding the effects of balanced energy and protein (BEP) supplements on gestational weight gain (GWG) and how the effects differ depending on maternal characteristics and the nutritional composition of the supplements will inform the implementation of prenatal BEP interventions. Methods and findings Individual participant data from 11 randomized controlled trials of prenatal BEP supplements (N = 12,549, with 5,693 in the BEP arm and 6,856 in the comparison arm) in low- and middle-income countries were used. The primary outcomes included GWG adequacy (%) and the estimated total GWG at delivery as continuous outcomes, and severely inadequate (<70% adequacy), inadequate GWG (<90% adequacy), and excessive GWG (>125% adequacy) as binary outcomes; all variables were calculated based on the Institute of Medicine recommendations. Linear and log-binomial models were used to estimate study-specific mean differences or risk ratios (RRs), respectively, with 95% confidence intervals (CIs) of the effects of prenatal BEP on the GWG outcomes. The study-specific estimates were pooled using meta-analyses. Subgroup analyses were conducted by individual characteristics. Subgroup analyses and meta-regression were conducted for study-level characteristics. Compared to the comparison group, prenatal BEP led to a 6% greater GWG percent adequacy (95% CI: 2.18, 9.56; p = 0.002), a 0.59 kg greater estimated total GWG at delivery (95% CI, 0.12, 1.05; p = 0.014), a 10% lower risk of severely inadequate GWG (RR: 0.90; 95% CI: 0.83, 0.99; p = 0.025), and a 7% lower risk of inadequate GWG (RR: 0.93; 95% CI: 0.89, 0.97; p = 0.001). The effects of prenatal BEP on GWG outcomes were stronger in studies with a targeted approach, where BEP supplements were provided to participants in the intervention arm under specific criteria such as low body mass index or low GWG, compared to studies with an untargeted approach, where BEP supplements were provided to all participants allocated to the intervention arm. Conclusions Prenatal BEP supplements are effective in increasing GWG and reducing the risk of inadequate weight gain during pregnancy. BEP supplementation targeted toward pregnant women with undernutrition may be a promising approach to delivering the supplements.
The effects of prenatal multiple micronutrient supplementation and small-quantity lipid-based nutrient supplementation on small vulnerable newborn types in low-income and middle-income countries: A meta-analysis of individual participant data
(Journal Article, 2025-02) Wang, Dongqing; Liu, Enju; Perumal, Nandita; Partap, Uttara; Cliffer, Ilana R.; Costa, Janaína Calu; Wang, Molin; Fawzi, Wafaie W.; Adu-Afarwuah, Seth; Ashorn, Per; Ashorn, Ulla; Mridha, Malay Kanti; Arifeen, Shams; Bhutta, Zulfiqar A.; Cheng, Yue; Christian, Parul; Costello, Anthony M.; Dewey, Kathryn G.; Friis, Henrik; Gomo, Exnevia; Grais, Rebecca; Guindo, Ousmane; Krebs, Nancy F.; Huybregts, Lieven; Isanaka, Sheila; Lachat, Carl; Lartey, Anna; LeClerq, Steven C.; Maleta, Kenneth; Manandhar, Dharma S.; Martorell, Reynaldo; Matias, Susana L.; McClure, Elizabeth M.; Moore, Sophie E.; Osrin, David; Urassa, Willy; Pembe, Andrea B.; Prentice, Andrew M.; Ramakrishnan, Usha; Rivera, Juan; Rizvi, Arjumand; Roberfroid, Dominique; Shamim, Abu Ahmed; Soofi, Sajid; Schulze, Kerry; West Jr., Keith P.; Wu, Lee; Zeng, Lingxia; Zhu, Zhonghai
Background Small vulnerable newborn types, defined by combinations of being born too soon or too small, have distinct determinants and health consequences. We aimed to assess the effects of prenatal multiple micronutrient supplementation (MMS) and small-quantity lipid-based nutrient supplementation (SQ-LNS) on small vulnerable newborn types, which are currently unknown. Methods In this meta-analysis, individual participant data from randomised controlled trials of MMS and randomised controlled trials of SQ-LNS in low-income and middle-income countries were used. We systematically searched the literature using PubMed, Embase, and Web of Science to identify randomised controlled trials of prenatal nutritional supplementation using MMS or SQ-LNS among pregnant people published between Jan 1, 2000, and Dec 31, 2021. Studies were excluded if they were conducted exclusively among participants selected by pre-existing health conditions, such as anaemia status, HIV infection, or diabetes. We contacted the corresponding authors of all identified studies to seek data contribution. As individual participant data became available, we mapped relevant variables and harmonised the data across studies. Iron and folic acid supplementation was the control group in most studies. Newborns were classified into ten groups through the combinations of preterm or term birth, small, appropriate, and large for gestational age, and low birthweight (LBW) or non-LBW. Newborns were also analysed using a four-group categorisation of preterm or term and LBW or non-LBW. Log-binomial models were used to estimate study-specific risk ratios (RRs), which were pooled using meta-analyses. Findings 14 randomised controlled trials of MMS (n=42 618; the mean maternal age at study enrolment was 24·3 years [SD 5.6]; 22 086 [51·8%] male neonates and 20 532 [48·2%] female neonates) and four randomised controlled trials of SQ-LNS (n=6246; the mean maternal age at study enrolment was 23·3 years [SD 5·3]; 3137 [50·2%] male neonates and 3109 [49·8%] female neonates) were used. In the ten-group categorisation of small vulnerable newborns, prenatal MMS reduced the risk of preterm–small for gestational age (SGA)–LBW (RR 0·73, 95% CI 0·64–0·84; p=0·0003); preterm–appropriate for gestational age (AGA)–LBW (0·82, 0·74–0·91; p=0·0010); preterm–AGA–non-LBW (0·89, 0·80–0·98; p=0·019); term–SGA–LBW (0·91, 0·85–0·96; p=0·0046); and term–SGA–non-LBW (0·95, 0·90–1·00; p=0·050). In the four-group categorisation, prenatal MMS reduced the risk of preterm–SGA (0·71, 0·62–0·82; p=0·0002) and term–SGA (0·93, 0·89–0·98; p=0·0066). Prenatal SQ-LNS had no significant effects on the risk of giving birth to small vulnerable newborns except for preterm–large for gestational age–non-LBW in the ten-group categorisation (0·78, 0·65–0·94; p=0·023). Interpretation Prenatal MMS and SQ-LNS reduce the risk of giving birth to small vulnerable newborns to varying extents, with the greatest magnitude of effects observed for small vulnerable newborn types that confer the greatest neonatal mortality risk. This study underscores the importance of nutritional supplements in prenatal care.
Seed certification, certified seeds use and yield outcomes in Nigeria: Insights from nationally-representative farm panel data and seed company location data
(Journal Article, 2025-03) Takeshima, Hiroyuki; Ragasa, Catherine; Bamiwuye, Temilolu; Andam, Kwaw S.; Spielman, David J.; Edeh, Hyacinth O.; Fasoranti, Adetunji; Haile, Beliyou; Nwagboso, Chibuzo; Omoigui, Lucky O.; Abdoulaye, Tahirou; Kumar, P. Lava; Wossen, Tesfamicheal
CONTEXT Despite the importance of enhanced seed quality to agricultural productivity growth, evidence remains scarce regarding the nature and possible drivers of returns to formal sector quality assurance systems, including certified seeds production in countries like Nigeria that focus significantly on the formal-sector seed systems. OBJECTIVE This study narrows this knowledge gap by estimating the effect of the quantity of certified seeds produced and the spatial variations where they are produced on the use of certified seeds and yields. We also assess the yield effects of certified seeds use and their relationship with agroclimatic and socioeconomic conditions. METHODS We combine nationally-representative farm-household survey panel data with spatial data on the headquarters locations of seed companies, the quantity of certified seeds for maize, cowpea, and rice that they produce, and spatially explicit agroecological data. We apply panel fixed effects methods as well as instrumental-variable methods to address potential endogeneity associated with certified seeds use while also controlling for the use of improved varieties to separate their effects from the effects of certified seeds. RESULTS AND CONCLUSIONS Our findings indicate that the availability of certified seeds—captured by indicators of certified seeds produced by seed companies headquartered in the states of survey respondents—is associated with positive but declining marginal effects on certified seeds use and yields. These results are robust when we also consider the potential within-state heterogeneity in the proximity to seed company headquarters, as well as potential spillovers from the nearest adjacent states. The yield effects of certified seeds are heterogeneous and depend on agroclimatic conditions and farmers' socioeconomic characteristics. The use of certified seeds is somewhat higher in areas with higher yield effects after controlling for certified seeds production. These patterns partly lead to observed non-linearities in certified seeds use because certified seeds may be more likely to be used by farmers with higher expected returns than farmers with lower expected returns. These results underscore the importance of spatially targeted efforts in enhancing certified seeds production capacity, together with the exploration of intermediate quality standards in the short term where costs of seed certification are high relative to returns. SIGNIFICANCE The study provides unique quantitative evidence in a nationally representative framework in an African country that returns to seed certification systems in the current setting significantly vary depending on contexts, including agroclimatic conditions.
Maize yield responsiveness and profitability of fertilizer: New survey evidence from six African countries
(Journal Article, 2025-05) Ragasa, Catherine; Takeshima, Hiroyuki; Asante, Seth; Amare, Mulubrhan; Ma, Ning; Olanrewaju, Opeyemi; Duchoslav, Jan
Enhancing maize productivity growth is pivotal for revolutionizing the agrifood system in Africa, with inorganic fertilizer serving as a fundamental input for catalyzing this progress. However, concerns are mounting about the low and decreasing yield response and profitability of inorganic fertilizer use, particularly in Sub-Saharan Africa. This study aims to refine yield response and profitability models by incorporating recent data from nationally representative and panel datasets spanning six countries. Most countries exhibited low nitrogen yield responsiveness (4–7 kg), while Ghana and Uganda showed higher responsiveness (15–20 kg) per additional 1 kg of nitrogen. Analysis of fertilizer-to-maize price ratios from 2010 to 2023 showed a downward trend, with spikes in 2022 in Ghana, Malawi, Nigeria, and Tanzania. Overall, except for those years, the data suggest a trend of increasingly favorable price incentives for fertilizer use. Ethiopia, Tanzania, and Uganda experienced declines in the fertilizer-to-maize price ratio. Increasing inorganic fertilizer use would be profitable in Ethiopia, Ghana, Nigeria, and Uganda at current market prices, but not in Malawi or Tanzania. Subsidies in Malawi and Tanzania have boosted profitability, but these may not be necessary in Ghana, Nigeria, or Uganda, which already have favorable price incentives; Malawi could benefit by substantially reducing its 80 percent subsidy while maintaining decent price incentives and farm profits. The paper proposes policy options based on factors influencing yield responsiveness and potential improvements drawn from new modeling and synthesis of the literature.
Comment la croissance rapide de la Chine peut-elle profi ter aux pauvres d’Afrique grâce au développement rural et agricole
(Journal Article, 2008) Fan, Shenggen
Prevalence of diabetes and prediabetes in South Asian countries: A systematic review and meta-analysis
(Journal Article, 2025-01) Ali, Masum; Alam, Md Mahbub; Rifat, M. A.; Simi, Sonjida Mesket; Sarwar, Sneha; Amin, Md Ruhul; Saha, Sanjib
Introduction South Asia is observing an epidemiological transition from communicable to non-communicable diseases where diabetes is an important marker. In this study, we estimate the overall prevalence of diabetes and prediabetes in South Asian countries. Method A systematic literature review and meta-analysis is performed to estimate the prevalence of diabetes and prediabetes in Bangladesh, India, Nepal, Pakistan, Sri Lanka, Bhutan, the Maldives, and Afghanistan using studies based on only the nationally representative surveys and published from 2012 until June 2024. The quality of the included articles was assessed using the Newcastle–Ottawa Scale. Both random-effect (Der Simonian-Laird inverse variance) and fixed-effect models were used to perform meta-analyses followed by meta-regression. Results We identified 64 studies for diabetes and 14 studies for prediabetes, covering a total of 4,613,487 and 156,407 participants, respectively. Overall, the pooled prevalence of diabetes and prediabetes was 8.56% (95% CI 5.73–11.91; I2 = 99.99%) and 18.99% (95% CI 12.74–26.6; I2 = 99.87%), respectively, with high heterogeneity observed among the studies based on random-effect models. We also found that the prevalence of diabetes identified by clinical methods was higher than the self-reported measures. Conclusion The analyses revealed that the prevalence of diabetes and prediabetes in South Asia throughout the study period is significantly elevated. This necessitates the establishment of comprehensive guidelines for South Asians to mitigate the escalating prevalence of diabetes and prediabetes.
A scalable crop yield estimation framework based on remote sensing of solar-induced chlorophyll fluorescence (SIF)
(Journal Article, 2024-04) Kira, Oz; Wen, Jiaming; Han, Jimei; McDonald, Andrew J.; Barrett, Christopher B.; Ortiz-Bobea, Ariel; Liu, Yanyan; You, Liangzhi; Mueller, Nathaniel D.; Sun, Ying
Projected increases in food demand driven by population growth coupled with heightened agricultural vulnerability to climate change jointly pose severe threats to global food security in the coming decades, especially for developing nations. By providing real-time and low-cost observations, satellite remote sensing has been widely employed to estimate crop yield across various scales. Most such efforts are based on statistical approaches that require large amounts of ground measurements for model training/calibration, which may be challenging to obtain on a large scale in developing countries that are most food-insecure and climate-vulnerable. In this paper, we develop a generalizable framework that is mechanism-guided and practically parsimonious for crop yield estimation. We then apply this framework to estimate crop yield for two crops (corn and wheat) in two contrasting regions, the US Corn Belt US-CB, and India's Indo–Gangetic plain Wheat Belt IGP-WB, respectively. This framework is based on the mechanistic light reactions (MLR) model utilizing remotely sensed solar-induced chlorophyll fluorescence (SIF) as a major input. We compared the performance of MLR to two commonly used machine learning (ML) algorithms: artificial neural network and random forest. We found that MLR-SIF has comparable performance to ML algorithms in US-CB, where abundant and high-quality ground measurements of crop yield are routinely available (for model calibration). In IGP-WB, MLR-SIF significantly outperforms ML algorithms. These results demonstrate the potential advantage of MLR-SIF for yield estimation in developing countries where ground truth data is limited in quantity and quality. In addition, high-resolution and crop-specific satellite SIF is crucial for accurate yield estimation. Therefore, harnessing the mechanism-guided MLR-SIF and rapidly growing satellite SIF measurements (with high resolution and crop-specificity) hold promise to enhance food security in developing countries towards more effective responses to food crises, agricultural policies, and more efficient commodity pricing.
Front-of-pack labels and young consumers: An experimental investigation of nutrition and sustainability claims in Chile
(Journal Article, 2025-06) Fretes, Gabriela; Wilson, Norbert L.W.; Corvalan, Camila; Economos, Christina D.; Cash, Sean B.
HIV/AIDs and food and nutrition security: what is known and what can be done?
(Journal Article, 2005) Gillespie, Stuart
Program evaluation with unobserved heterogeneity and selective implementation: the Mexican Progresa impact on child nutrition
(Journal Article, 2005-08) Behrman, Jere R.; Hoddinott, John F.
This paper considers the impact of Programa de Educación, Salud y Alimentación (PROGRESA), a large Mexican rural anti‐poverty programme that had an evaluation sample in which overall treatment was randomly assigned to some communities but not others, on child nutrition. When we examine the impact of PROGRESA based on the presumption of randomized allocations, we find that PROGRESA had no or even a negative impact on child nutrition. However, not all children designated to receive nutritional supplements actually did so. Our preferred estimates – child fixed‐effects estimates that control for unobserved heterogeneity that is correlated with access to the supplement – indicate a significantly positive and fairly substantial programme effect of the nutritional supplements on children 12–36 months. They imply an increase of about a sixth in mean growth per year for these children and a lower probability of stunting. Effects are somewhat larger for children from poorer communities but whose mothers are functionally literate. The long‐term consequences of these improvements are non‐trivial; its impact working through adult height alone could result in a 2.9% increase in lifetime earnings.
An overview of regulation, perceptions and priorities for GM crops in Asian countries
(Journal Article, 2005) Mehta-Bhatt, Purvi; Ebora, Reynaldo V.; Cohen, Joel I.; Falck-Zepeda, José Benjamin; Zambrano, Patricia

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