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Corral, Paul

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Human Development

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Last updated May 4, 2023

Biography

Paul Corral is a senior economist in the Office of the HD Chief Economist at the World Bank. He previously worked as a data scientist with the Poverty and Equity Global Practice, where he focused on small area estimation methods and applications. He has published peer-reviewed articles on agriculture and development for specific African countries and is the author of multiple Stata commands. He holds a PhD in economics from American University and an MSc degree in agricultural economics from the University of Hohenheim.

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Now showing 1 - 10 of 16

Explaining Gender Differentials in Agricultural Production in Nigeria

(World Bank, Washington, DC, 2014-03) Oseni, Gbemisola ; Corral, Paul ; Goldstein, Markus ; Winters, Paul

This paper uses data from the General Household Survey Panel 2010/11 to analyze differences in agricultural productivity across male and female plot managers in Nigeria. The analysis utilizes the Oaxaca-Blinder decomposition method, which allows for decomposing the unconditional gender gap into (i) the portion caused by observable differences in the factors of production (endowment effect) and (ii) the unexplained portion caused by differences in returns to the same observed factors of production (structural effect). The analysis is conducted separately for the North and South regions, excluding the west of the country. The findings show that in the North, women produce 28 percent less than men after controlling for observed factors of production, while there are no significant gender differences in the South. In the decomposition results, the structural effect in the North is larger than the endowment at the mean. Although women in the North have access to less productive resources than men, the results indicate that even if given the same level of inputs, significant differences still emerge. However for the South, the decomposition results show that the endowment effect is more important than the structural effect. Access to resources explains most of the gender gap in the South and if women are given the same level of inputs as men, the gap will be minimal. The difference in the results for the North and South suggests that policy should vary by region.
No Condition is Permanent: Middle Class in Nigeria in the Last Decade

(World Bank Group, Washington, DC, 2015-03) Corral, Paul ; Molini, Vasco ; Oseni, Gbemisola

The economic debate on existence and definition of the middle class has become particularly lively in many developing countries. Despite this growing interest, the identification of the middle class group in these countries remains quite challenging. Building on a recently developed framework to define the middle class, this paper tries to estimate the Nigerian middle class size in a rigorous quantitative manner. By exploiting publicly available panel data, the expenditure associated to a 10 percent probability of falling into poverty is estimated, and this is used as the middle class threshold for Nigeria. The threshold expenditure for the middle class in Nigeria is found to be 378.39 Naira per capita per day (2010 PPP). Relying on this threshold and through survey-to-survey imputation the size of Nigeria's middle class in 2003 is also estimated. The results show that there has been considerable improvement on the size of the middle class and poverty reduction between 2003 and 2013. Poverty decreased between 2003 and 2013 from 45 to 33 percent, while the middle class increased from 13 percent to 19 percent. Nevertheless the results still paint a heterogeneous picture of poverty and the middle class in Nigeria, where the largest portion of the population, although above the poverty threshold, continues to live with average or high vulnerability to poverty.
Agricultural Commercialisation and Food Security in Rural Economies: Malawian Experience

(Taylor and Francis, 2017-02-02) Radchenko, Natalia ; Corral, Paul

This paper contributes to the debate on the nutrition-related outcomes of cash crop adoption by using a model with essential heterogeneity and a semi-parametric estimation technique. The model explicitly frames non-separability between production and consumption decisions of farming households providing an original test of separability. The empirical application is run using Malawian data. The results imply rational anticipations and decision process of agrarian households relative to the crop portfolio choice, disparate strength of market barriers faced by the farmers, non-separability between production and consumption decisions and a weak transmission from agricultural incomes to higher food expenditures and better diet.
Explaining Gender Differentials in Agricultural Production in Nigeria

(World Bank, Washington, DC, 2013-10) Oseni, Gbemisola ; Corral, Paul ; Goldstein, Markus ; Winters, Paul

Nigeria presents a unique case study on differences in agricultural productivity between men and women. This study, which captures a comprehensive picture of agriculture across the nation, shows that female farmers produce 16 percent less per hectare than their male counterparts, when plot size, farmer characteristics, and inputs are taken into account. This gender gap is driven by the North East and Central zones located in the Northern region of the country, where female farmers are 28 percent less productive than male farmers. In this region, women, particularly those who are older, farm on smaller plots and have lower levels of key inputs, notably fertilizer and labor, which is a well-documented pattern in many African contexts. The Southern region, however, does not fit this established pattern. When controlling for key characteristics and factors of production, in the South no gender gap in productivity is observed, though female farmers will benefit from additional herbicide and female labor. The notably different patterns in these two regions of the same country provide ample space for further study. Thus, in order to decrease the country-wide gender gap in production, the authors recommend extending access to fertilizer, hired labor, and cash crops to women - particularly those in the North.
Fragility and Conflict: On the Front Lines of the Fight against Poverty

(Washington, DC: World Bank, 2020-02-27) Corral, Paul ; Irwin, Alexander ; Krishnan, Nandini ; Mahler, Daniel Gerszon ; Vishwanath, Tara

Fragility and conflict pose a critical threat to the global goal of ending extreme poverty. Between 1990 and 2015, successful development strategies reduced the proportion of the world’s people living in extreme poverty from 36 to 10 percent. But in many fragile and conflict-affected situations (FCS), poverty is stagnating or getting worse. The number of people living in proximity to conflict has nearly doubled worldwide since 2007. In the Middle East and North Africa, one in five people now lives in such conditions. The number of forcibly displaced persons worldwide has also more than doubled in the same period, exceeding 70 million in 2017. If current trends continue, by the end of 2020, the number of extremely poor people living in economies affected by fragility and conflict will exceed the number of poor people in all other settings combined. This book shows why addressing fragility and conflict is vital for poverty goals and charts directions for action. It presents new estimates of welfare in FCS, filling gaps in previous knowledge, and analyzes the multidimensional nature of poverty in these settings. It shows that data deprivation in FCS has prevented an accurate global picture of fragility, poverty, and their interactions, and it explains how innovative new measurement strategies are tackling these challenges. The book discusses the long-term consequences of conflict and introduces a data-driven classification of countries by fragility profile, showing opportunities for tailored policy interventions and the need for monitoring multiple markers of fragility. The book strengthens understanding of what poverty reduction in FCS will require and what it can achieve.
No Condition Is Permanent: Middle Class in Nigeria in the Last Decade

(Taylor and Francis, 2017-09-21) Corral Rodas, Paul Andres ; Molini, Vasco ; Oseni, Gbemisola

The economic debate on the existence and definition of the middle class has become particularly lively in many developing countries. Building on a recently developed framework called the Vulnerability Approach to Middle Class (VAMC) to define the middle class, this paper tries to estimate the size of the Nigerian middle class in a rigorous quantitative manner and to gauge its evolution over time. Using the VAMC method, the middle class group can be defined residually from the vulnerability analysis as those for which the probability of falling into poverty is below a certain threshold. The results show that there has been considerable improvement in the size of the Nigerian middle class from 13 per cent in 2003/4 to 19 per cent in 2012/13. However, the rate has been slower than expected given the high growth rates experienced in the country over the same period. The results also paint a heterogeneous picture of the middle class in Nigeria with large spatial differences. The southern regions have a higher share and experienced more growth of the middle class compared with the northern regions.
Heterogeneous Returns to Income Diversification: Evidence from Nigeria

(World Bank, Washington, DC, 2016-11) Bertoni, Eleonora ; Corral, Paul ; Molini, Vasco ; Oseni, Gbemisola

This paper investigates the impact of income diversification on farming households' welfare in Nigeria on two rounds of the Nigeria General Household Survey-Panel, namely the 2010/2011 and 2012/2013. The study finds that income diversification is the norm in Nigeria, with about 60 percent of farmers diversifying away from subsistence farming into non-farm activities and cash crops. In addition, using the panel of farmers interviewed before and after a severe drought that hit Northern Nigeria in particular in 2011, the study finds that diversification increased throughout Nigeria from 60 to 64 percent and in the North from 58 to 63 percent. The study postulates the existence of heterogeneous returns on diversification as a consequence of the drought, and estimates the returns through a non-parametric selection model using a local instrumental variable. The choice of this model is dictated by the necessity to account for both heterogeneous effects of diversification and selection bias related to households' decision to diversify. Overall, it is found that diversification positively affects consumption in Nigeria. However, who benefits the most is crucially determined by the initial conditions under which diversification is undertaken and the specific agro-climatic context in which households operate.
Pull Your Small Area Estimates Up by the Bootstraps

(Taylor and Francis, 2021-05-08) Corral, Paul ; Molina, Isabel ; Nguyen, Minh

This paper presents a methodological update to the World Bank's toolkit for small area estimation. The paper reviews the computational procedures of the current methods used by the institution: the traditional ELL approach and the Empirical Best (EB) addition introduced to imitate the original EB procedure of Molina and Rao [Small area estimation of poverty indicators. Canadian J Stat. 2010;38(3):369–385], including heteroskedasticity and survey weights, but using a different bootstrap approach, here referred to as clustered bootstrap. Simulation experiments provide empirical evidence of the shortcomings of the clustered bootstrap approach, which yields biased and noisier point estimates. The document presents an update to the World Bank’s EB implementation by considering the original EB procedures for point and noise estimation, extended for complex designs and heteroscedasticity. Simulation experiments illustrate that the revised methods yield considerably less biased and more efficient estimators than those obtained from the clustered bootstrap approach.
Poverty, Inequality, and Agriculture in the EU

(World Bank, Washington, DC, 2018-11) Azevedo, Joao Pedro ; van den Brink, Rogier J. E. ; Corral, Paul ; Avila, Montserrat ; Zhao, Hongxi ; Mostafavi, Mohammad-Hadi

Boosting convergence and shared prosperity in the European Union achieved renewed urgency after the global financial crisis of 2008. This paper assesses the role of agriculture and the Common Agricultural Program in achieving this. The paper sheds light on the relationship between poverty and agriculture as part of the process of structural transformation. It positions each member country on the path toward a successful structural transformation. The paper then evaluates at the regional level where the Common Agricultural Program funding tends to go, poverty-wise, within each country. This approach enables making more informed policy recommendations on the current state of the Common Agricultural Program funding, as well as evaluating the role of agriculture as a driver of shared prosperity. The analysis performed throughout the paper uses a combination of data sources at several spatial levels.
Agricultural Commercialization and Nutrition Revisited: Empirical Evidence from Three African Countries

(Elsevier, 2017-02) Carletto, Calogero ; Corral, Paul ; Guelfi, Anita

The transition from subsistence to commercial agriculture is key for economic growth. But what are the consequences for nutritional outcomes? The evidence to date has been scant and inconclusive. This study contributes to the debate by revisiting two prevailing wisdoms: (a) market participation by African smallholders remains low; and (b) the impact of commercialization on nutritional outcomes is generally positive. Using nationally representative data from three African countries, the analysis reveals high levels of commercialization by even the poorest and smallest landholders, with rates of market participation as high as 90%. Female farmers participate less, but tend to sell larger shares of their production, conditional on participation. Second, we find little evidence of a positive relationship between commercialization and nutritional status. As countries and international agencies prioritize the importance of nutrition-sensitive agriculture, better understanding of the transmission channels between crop choices and nutritional outcomes should remain a research priority.