Person:
Jolliffe, Dean
Author Name Variants
Fields of Specialization
Food security,
Education economics,
Health economics,
Data collection methods,
Measuring Poverty
Degrees
ORCID
External Links
Departments
Development Economics Data Group, The World Bank
Externally Hosted Work
Contact Information
Last updated
August 29, 2023
Biography
Dean Jolliffe is a lead economist in the Development Data Group at the World Bank. He is a member of the Living Standards Measurement Study team and co-lead of the team that works on global poverty measurement (PovcalNet). Previously, he worked in the Research Group and the South Asia region of the World Bank. Prior to joining the World Bank, he was a research economist with the Economic Research Service of the U.S. Department of Agriculture, an assistant professor at Charles University Center for Economic Research and Graduate Education in Prague, an adjunct professor at Johns Hopkins University School of Advanced International Studies, an adjunct professor at Georgetown University Public Policy Institute, and a postdoctoral fellow at the International Food Policy Research Institute. Dean holds appointments as a research fellow with the Institute for the Study of Labor, as a co-opted council member of the International Association for Research in Income and Wealth, and as a fellow of the Global Labor Organization. He received his PhD in economics from Princeton University.
Publication Search Results
1 - 8 of 8
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Publication
Estimating Poverty with Panel Data, Comparably: An Example from Jordan
(World Bank, Washington, DC, 2015-07)Poverty estimates based on enumeration from a single point in time form the cornerstone for much of the literature on poverty. Households are typically interviewed once about their consumption or income, and their wellbeing is assessed from their responses. Global estimates of poverty that aggregate poverty counts from all countries implicitly assume that the counts are comparable. This paper illustrates that this assumption of comparability is potentially invalid when households are interviewed multiple times with repeat visits throughout the year. The paper provides an example from Jordan, where the internationally comparable approach of handling the data from repeat visits yields a poverty rate that is 26 percent greater than the rate that is currently reported as the official estimate. The paper also explores alternative definitions of poverty, informed in part by the psychological and biophysical literature on the long-run effects of short-term exposure to poverty or generally adverse environments. This alternative concept of poverty suggests that the prevalence of those who have been affected by poverty in Jordan during 2010 is more than twice as large as the official 2010 estimate of poverty. -
Publication
A Global Count of the Extreme Poor in 2012: Data Issues, Methodology and Initial Results
(World Bank, Washington, DC, 2015-10)The 2014 release of a new set of purchasing power parity conversion factors (PPPs) for 2011 has prompted a revision of the international poverty line. In order to preserve the integrity of the goalposts for international targets such as the Sustainable Development Goals and the World Bank’s twin goals, the new poverty line was chosen so as to preserve the definition and real purchasing power of the earlier $1.25 line (in 2005 PPPs) in poor countries. Using the new 2011 PPPs, the new line equals $1.90 per person per day. The higher value of the line in US dollars reflects the fact that the new PPPs yield a relatively lower purchasing power of that currency vis-à-vis those of most poor countries. Because the line was designed to preserve real purchasing power in poor countries, the revisions lead to relatively small changes in global poverty incidence: from 14.5 percent in the old method to 14.1 percent in the new method for 2011. In 2012, the new reference year for the global count, we find 12.7 percent of the world’s population, or 897 million people, are living in extreme poverty. There are changes in the regional composition of poverty, but they are also relatively small. This paper documents the detailed methodological decisions taken in the process of updating both the poverty line and the consumption and income distributions at the country level, including issues of inter-temporal and spatial price adjustments. It also describes various caveats, limitations, perils and pitfalls of the approach taken. -
Publication
Global Poverty Goals and Prices: How Purchasing Power Parity Matters
(World Bank, Washington, DC, 2015-05)With the recent release of the 2011 purchasing power parity (PPP) data from the International Comparison Program (ICP), analysts and institutions are confronted with the question of whether and how to use them for global poverty estimation. The previous round of PPP data from 2005 led to a large increase in the estimated number of poor in the world. The 2011 price data suggest that developing countries’ incomes in PPP-adjusted dollars are significantly higher than indicated by the 2005 PPP data. This has created the anticipation that the new PPP data will decrease significantly the count of poor people in the world. This paper presents evidence that if the global poverty line is updated with the 2011 PPP data based on the same set of national poverty lines that define the $1.25 line in 2005 PPPs, and if the 2011 PPP conversion factors are used without adjustments to selected countries, the 2011 poverty rate is within half a percentage point of the current global estimate based on 2005 PPPs. The analysis also indicates that the goal of ‘ending’ extreme poverty by 2030 continues to be an ambitious one. -
Publication
Estimating International Poverty Lines from Comparable National Thresholds
(Washington, DC, 2016-03)World Bank's international poverty line of $1.90/day, at 2011 purchasing power parity, is based on a collection of national poverty lines, which were originally used to set the international poverty line of $1.25/day at 2005 purchasing power parity. This paper proposes an approach for estimating a more recent, complete, and comparable collection of national poverty thresholds from reported national poverty rates. The paper presents a set of international poverty lines based on this new database of national poverty lines. In contrast to the lines used to estimate the $1.90 international poverty line, this approach produces national poverty lines that are (1) consistent with national poverty rates, (2) expressed in common units, and (3) provide greater support to the estimated international poverty line. These national poverty lines are used to estimate an extreme international poverty line, and three higher lines that are more relevant for higher-income countries. A key finding provides evidence of the robustness and relevance of the $1.90 international poverty line as a measure of extreme poverty for low-income countries. -
Publication
Food Security and Wheat Prices in Afghanistan : A Distribution-sensitive Analysis of Household-level Impacts
(World Bank, Washington, DC, 2012-04)This paper investigates the impact of increases in wheat flour prices on household food security using unique nationally-representative data collected in Afghanistan from 2007 to 2008. It uses a new estimator, the Unconditional Quantile Regression estimator, based on influence functions, to examine the marginal effects of price increases at different locations on the distributions of several food security measures. The estimates reveal that the negative marginal effect of a price increase on food consumption is two and a half times larger for households that can afford to cut the value of food consumption (75th quantile) than for households at the bottom (25th quantile) of the food-consumption distribution. Similarly, households with diets high in calories reduce intake substantially, but those at the bottom of the calorie distribution (25th quantile) make very small changes in intake as a result of the price increases. In contrast, households at the bottom of the dietary diversity distribution make the largest adjustments in the quality of their diets, since such households often live at subsistence levels and cannot make large cuts in caloric intake without suffering serious health consequences. These results provide empirical evidence that when faced with staple-food price increases, food-insecure households sacrifice quality (diversity) in order to protect calories. The large differences in behavioral responses of households that lie at the top and bottom of these distributions suggest that policy analyses relying solely on ordinary least squares estimates may be misleading. -
Publication
Rising Food Prices and Coping Strategies : Household-level Evidence from Afghanistan
( 2010-11-01)This paper investigates the impact of rising wheat prices -- during the 2007/08 global food crisis -- on food security in Afghanistan. Exploiting the temporal stratification of a unique nationally-representative household survey, the analysis finds evidence of large declines in real per capita food consumption and in food security (per capita calorie intake and household dietary diversity) corresponding to the price shocks. The data reveal smaller price elasticities with respect to calories than with respect to food consumption, suggesting that households trade off quality for quantity as they move toward staple foods and away from nutrient-rich foods such as meat and vegetables. In addition, there is increased demand in the face of price increases (Giffen good properties) for wheat products in urban areas. This study improves on country-level simulation studies by providing estimates of actual household wellbeing before and during the height of the global food crisis in one of the world's poorest, most food-insecure countries. -
Publication
Food Counts - Measuring Food Consumption and Expenditures in Household Consumption and Expenditure Surveys: Introduction to the Special Issue
(Elsevier, 2017-10)This introductory paper presents the results of an international multi-disciplinary research project on the measurement of food consumption in national household surveys. Food consumption data from household surveys are possibly the single most important source of information on poverty, food security, and nutrition outcomes at national, sub-national and household level, and contribute building blocks to global efforts to monitor progress towards the major international development goals. The paper synthesizes case studies from a diverse set of developing and OECD countries, looking at some of the main outstanding research issues as identified by a recent international assessment of 100 existing national household surveys (Smith et al., 2014). The project mobilized expertise from different disciplines (statistics, economics, food security, nutrition) to work towards enhancing our understanding of how to improve the quality and availability of food consumption and expenditure data, while making them more valuable for a diverse set of users. The individual studies summarized in this paper analyze, both theoretically and empirically, how different surveys design options affect the quality of the data being collected and, in turn, the implications for statistical inference and policy analysis. The conclusions and recommendations derived from this collection of studies will be instrumental in advancing the methodological agenda for the collection of household level food data, and will provide national statistical offices and survey practitioners worldwide with practical insights for survey design, while providing poverty, food and nutrition policymakers with greater understanding of these issues, as well as improved tools for and better guidance in policy formulation. -
Publication
Data Gaps, Data Incomparability, and Data Imputation: A Review of Poverty Measurement Methods for Data-Scarce Environments
(World Bank, Washington, DC, 2017-12)This paper reviews methods that have been employed to estimate poverty in contexts where household consumption data are unavailable or missing. These contexts range from completely missing and partially missing consumption data in cross-sectional household surveys, to missing panel household data. The paper focuses on methods that aim to compare trends and dynamic patterns of poverty outcomes over time. It presents the various methods under a common framework, with pedagogical discussion on the intuition. Empirical illustrations are provided using several rounds of household survey data from Vietnam. Furthermore, the paper provides a practical guide with detailed instructions on computer programs that can be used to implement the reviewed techniques.