Essama-Nssah, Boniface

Person:
Essama-Nssah, Boniface

Fields of Specialization

Poverty and growth, Program evaluation, Social impact of public policy

Last updated January 31, 2023

Biography

B. Essama-Nssah worked for 17 years for the World Bank in Washington, DC, before he retired as a senior economist in 2011. During his tenure at the Bank, he performed economic analyses, prepared policy research and technical papers, and conducted an annual training course on impact evaluation methodologies for staff from the World Bank and client countries. Before joining the World Bank, Essama-Nssah worked for two years as a senior research associate on the Food and Nutrition Program at Cornell University, and for six years as head of the Economics Department and vice dean of the Faculty of Law and Economics of the University of Yaoundé, Cameroon. He currently works as a consultant focusing on poverty and growth incidence analysis, program evaluation, and analysis of the social impact of public policy. He holds a PhD in economics from the University of Michigan in Ann Arbor.

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Now showing 1 - 10 of 12

A Unified Framework for Pro-Poor Growth Analysis

(World Bank, Washington, D.C., 2004-09) Essama-Nssah, B.

Starting with a general impact indicator as an evaluation criterion, The author offers an integrative framework for a unified discussion of various concepts and measures of pro-poor growth emerging from the current literature. He shows that whether economic growth is considered pro-poor depends fundamentally on the choice of evaluative weights. In addition, the author's framework leads to a new indicator of the rate of pro-poor growth that can be interpreted as the equally distributed equivalent growth rate. This is a distribution-adjusted rate of growth that depends on the chosen level of inequality aversion. Illustrations based on data for Indonesia in the 1990s show a strong link between growth and poverty reduction in that country. A decomposition of the observed poverty outcomes reveals the extent to which changes in inequality have blunted the poverty impacts of both growth and contraction. Finally, the results also demonstrate that absolute and relative indicators of pro-poor growth can lead to conflicting conclusions from the same set of facts.
A Poverty-Focused Evaluation of Commodity Tax Options

(World Bank, Washington, DC, 2007-06) Essama-Nssah, B.

The difficulties faced by many developing countries in raising revenue from direct taxes have forced them to rely heavily on indirect taxes to finance development interventions. The purpose of this paper is to show how to identify socially desirable options for commodity taxation in the context of a poverty reduction strategy. Within the logic of social evaluation the author assesses tax options on the basis of value judgments underlying members of the additively separable class of poverty measures. The criterion hinges on both the pattern of consumption of each commodity and the price elasticity of the poverty measure used. An application of this methodology to data for Guinea shows that many components of food expenditure (particularly cereals, grains, and roots) would be good candidates for exemption from value-added tax. Even though expenditure on health and education is distributed in favor of the non-poor, their importance for human capital development argues for a program of targeted subsidies in a broader context of cost recovery.
Reading Tealeaves on the Potential Impact of the Privatization of Tea Estates in Rwanda

(World Bank, Washington, DC, 2008-03) Essama-Nssah, B. ; Ezemenari, Kene ; Korman, Vijdan

The Poverty Reduction Strategy of the Government of Rwanda seeks to unlock the growth and poverty reduction potential of the tea sector through the privatization of tea estates. This paper uses the logic of causal inference and data from the 2004 Quantitative Baseline Survey of the tea sector to assess the potential impact of the privatization program. This entails a normalized comparison of productivity outcomes to account for household heterogeneity in terms of observable and non-observable determinants of these outcomes. The paper also compares living standards between tea and non-tea households. Three main findings emerge from the analysis. Productivity outcomes are generally better in the private sector than in the public sector. Male-headed households outperform female-headed households along all dimensions considered here. And tea households tend to be better off than non-tea households.
Economy-wide and Distributional Impacts of an Oil Price Shock on the South African Economy

(World Bank, Washington, DC, 2007-09) Essama-Nssah, B. ; Go, Delfin S. ; Kearney, Marna ; Korman, Vijdan ; Robinson, Sherman ; Thierfelder, Karen

As crude oil prices reach new highs, there is renewed concern about how external shocks will affect growth and poverty in developing countries. This paper describes a macro-micro framework for examining the structural and distributional consequences of a significant external shock-an increase in the world price of oil-on the South African economy. The authors merge results from a highly disaggregative computable general equilibrium model and a micro-simulation analysis of earnings and occupational choice based on socio-demographic characteristics of the household. The model provides changes in employment, wages, and prices that are used in the micro-simulation. The analysis finds that a 125 percent increase in the price of crude oil and refined petroleum reduces employment and GDP by approximately 2 percent, and reduces household consumption by approximately 7 percent. The oil price shock tends to increase the disparity between rich and poor. The adverse impact of the oil price shock is felt by the poorer segment of the formal labor market in the form of declining wages and increased unemployment. Unemployment hits mostly low and medium-skilled workers in the services sector. High-skilled households, on average, gain from the oil price shock. Their income rises and their spending basket is less skewed toward food and other goods that are most affected by changes in oil prices.
Measuring the Pro-Poorness of Income Growth within an Elasticity Framework

(World Bank, Washington, DC, 2006-10) Essama-Nssah, B. ; Lambert, Peter J.

Poverty reduction has become a fundamental objective of development, and therefore a metric for assessing the effectiveness of various interventions. Economic growth can be a powerful instrument of income poverty reduction. This creates a need for meaningful ways of assessing the poverty impact of growth. This paper follows the elasticity approach to propose a measure of pro-poorness defined as a weighted average of the deviation of a growth pattern from the benchmark case. The measure can help assess pro-poorness both in terms of aggregate poverty measures, which are members of the additively separable class, and at percentiles. It also lends itself to a decomposition procedure, whereby the overall pattern of income growth can be unbundled, and the contributions of income components to overall pro-poorness identified. An application to data for Indonesia in the 1990s reveals that the amount of poverty reduction achieved over that period remains far below what would have been achieved under distributional neutrality. This conclusion is robust to the choice of a poverty measure among members of the additively separable class, and can be tracked back to changes in expenditure components.
Propensity Score Matching and Policy Impact Analysis : A Demonstration in EViews

(World Bank, Washington, DC, 2006-04) Essama-Nssah, B.

Effective development policymaking creates a need for reliable methods of assessing effectiveness. There should be, therefore, an intimate relationship between effective policymaking and impact analysis. The goal of a development intervention defines the metric by which to assess its impact, while impact evaluation can produce reliable information on which policymakers may base decisions to modify or cancel ineffective programs and thus make the most of limited resources. This paper reviews the logic of propensity score matching (PSM) and, using data on the National Support Work Demonstration, compares that approach with other evaluation methods such as double difference, instrumental variable, and Heckman's method of selection bias correction. In addition, it demonstrates how to implement nearest-neighbor and kernel-based methods, and plot program incidence curves in E-Views. In the end, the plausibility of an evaluation method hinges critically on the correctness of the socioeconomic model underlying program design and implementation, and on the quality and quantity of available data. In any case, PSM can act as an effective adjuvant to other methods.
The Poverty and Distributional Impact of Macroeconomic Shocks and Policies : A Review of Modeling Approaches

(World Bank, Washington, DC, 2005-08) Essama-Nssah, B.

The importance of distributional issues in policymaking creates a need for empirical tools to assess the social impact of economic shocks and policies. This paper reviews some of the modeling approaches that are currently in use at the World Bank and other international financial institutions. The specification of these models is dictated by the issues at stake, the knowledge about the nature of the process involved, and the availability and reliability of relevant data. Furthermore, shocks and policies have macroeconomic, structural, and distributional implications. This creates interdependence between such policy issues. Finally, the distributional impact of shocks and policies hinges on the heterogeneity of socioeconomic agents with respect to endowments and behavior. In the end, each modeling approach should be judged on how well it handles the interdependence between policy issues and the heterogeneity of the stakeholders, given other constraints.
Simulating the Poverty Impact of Macroeconomic Shocks and Policies

(World Bank, Washington, DC, 2005-12) Essama-Nssah, B.

Developing countries face a host of macroeconomic challenges in the design and implementation of development strategies and policies. The importance of the underlying poverty and distributional issues creates a need for relevant and reliable ways of tracking the social impact of shocks and policies. This paper describes and demonstrates the use of a stylized framework for simulating the poverty implications of the Dutch disease, a change in the terms of trade and budgetary policy. The basic approach is to embed a Lorenz model of the size distribution of economic welfare in a general equilibrium model of an open economy. It is observed that, while aggregate welfare and poverty effects may be negligible, the structural and distributional impacts tend to be significant. The latter drive the political economy of policymaking and point to the need for an analytical framework that accounts for both the structural richness of the economy and the heterogeneity of the stakeholders
Understanding Changes in Poverty

(World Bank Group, Washington, DC, 2014-08-12) Inchauste, Gabriela ; Azevedo, João Pedro ; Essama-Nssah, B. ; Olivieri, Sergio ; Van Nguyen, Trang ; Saavedra-Chanduvi, Jaime ; Winkler, Hernan

Understanding Changes in Poverty brings together different methods to decompose the contributions to poverty reduction. A simple approach quantifies the contribution of changes in demographics, employment, earnings, public transfers, and remittances to poverty reduction. A more complex approach quantifies the contributions to poverty reduction from changes in individual and household characteristics, including changes in the sectoral, occupational, and educational structure of the workforce, as well as changes in the returns to individual and household characteristics. Understanding Changes in Poverty implements these approaches and finds that labor income growth that is, growth in income per worker rather than an increase in the number of employed workers was the largest contributor to moderate poverty reduction in 21 countries experiencing substantial reductions in poverty over the past decade. Changes in demographics, public transfers, and remittances helped, but made relatively smaller contributions to poverty reduction. Further decompositions in three countries find that labor income grew mainly because of higher returns to human capital endowments, signaling increases in productivity, higher relative price of labor, or both. Understanding Changes in Poverty will be of particular relevance to development practitioners interested in better understanding distributional changes over time. The methods and tools presented in this book can also be applied to better understand changes in inequality or any other distributional change.
Accounting for Heterogeneity in Growth Incidence in Cameroon

( 2010-11-01) Essama-Nssah, B. ; Bassole, Leandre ; Paul, Saumik

This paper presents counterfactual decompositions based on both the Shapley method and a generalization of the Oaxaca-Blinder approach to identify proximate factors that might explain differences in the distribution of economic welfare in Cameroon in 1996-2007. In particular, the analysis uses re-centered influence function regressions to link the growth incidence curve for 2001-2007 to household characteristics and account for heterogeneity of impact across quantiles in terms of the composition (or endowment) effect and structural (or price) effect. The analysis finds that the level of the growth incidence curve is explained by the endowment effect while its shape is driven by the price effect. Observed gains at the bottom of the distribution are due to returns to endowments. The rest of the gains are accounted for by the composition effect. Further decomposition of these effects shows that the composition effect is determined mainly by household demographics while the structural effect is shaped by the sector of employment and geography. Finally, analysis of the rural-urban gap in living standards shows that, for the poorest households in both sectors, differences in household characteristics matter more than the returns to those characteristics. The opposite is true for better-off households.