Author Name Variants
Fields of Specialization
Poverty and growth, Program evaluation, Social impact of public policy
Externally Hosted Work
Last updated January 31, 2023
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.
Publication Search Results
Now showing 1 - 9 of 9
Publication(World Bank, Washington, DC, 2004-01) Essama-Nssah, B.A crucial step in policy analysis involves computing consequences of policy actions. The author shows how to implement numerically a general equilibrium model in EViews. Computable general equilibrium models are now commonly used in both industrial and developing countries to assess the impact of external shocks or economic policies on the structure of the economy or the distribution of welfare. The current version of EViews offers a set of tools for building and solving simulation models in general. The same tools make it possible to conduct policy analysis within a general equilibrium framework. Based on the generalized Salter-Swan framework and macroeconomic data for Indonesia, the author shows how to process a social accounting matrix, specify and calibrate the model, and run simulations. The results replicate welfare and structural effects of shocks and policies consistent with the underlying conceptual framework. They also reveal the key role played by structural parameters, such as the elasticity of export transformation and that of import substitution, in determining the extent of structural adjustment to shocks and the relevance of the policy response.
Publication(World Bank, Washington, DC, 2002-09) Essama-Nssah, B.Economic development necessarily changes the welfare of socioeconomic groups to various degrees, depending on differences in their social arrangements. The challenge for policymakers is to select the changes that will be most socially desirable. The author demonstrates the usefulness of distributional analysis for social evaluation and, more specifically, for welfare evaluation, using data from the 1994 Integrated Household Survey in Guinea. Because the international community has declared poverty eradication a fundamental objective of development, the author uses a poverty-focused approach to social evaluation based on the maximum principle. This principle offers a unifying framework for analyzing the socioeconomic impact of public policy by using a wide variety of evaluation functions, inequality indicators (like the extended Gini coefficient), and poverty indices (such as Sen's index and the members of the Foster-Greer-Thorbecke family). The author also examines, within the context of commodity taxation, how to identify socially desirable policy options using both the dominance criterion and abbreviated social welfare functions. He includes computer routines for calculating various welfare indices and for plotting the relevant concentration curves.
Publication(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.
Publication(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.
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.
Publication(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
Publication(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, HernanUnderstanding 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.
Publication( 2010-11-01) Essama-Nssah, B. ; Bassole, Leandre ; Paul, SaumikThis 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.
Publication( 2010-03-01) Essama-Nssah, B. ; Bassole, LeandreThe Government of Cameroon has declared poverty reduction through strong and sustainable economic growth the central objective of its socioeconomic policy. This paper uses available household survey data to assess the performance of the economy with respect to this objective over the period 1996-2007. The authors use counterfactual decompositions based on both the Shapley method and the generalized Oaxaca-Blinder framework to identify proximate factors that might explain differences in observed outcomes over time, across regions and households. The concept of pro-poorness provides a basis for a normative evaluation of these outcomes. The analysis of changes in the size distribution of economic welfare reveals that formal sector employment, access to credit, education, and urban residence are characteristics that bring significantly high returns to households. Employment in smallholder agriculture has a negative impact on welfare across quantiles. Economic growth was accompanied by significant poverty reduction between 1996 and 2001. But poverty barely decreased between 2001 and 2007 due to very weak growth. Over the same period, household investment in human capital took a serious hit. Given the additional finding that the pattern of growth is characterized by urban bias and regional disparity, the overall assessment is that economic growth has been weakly pro-poor in Cameroon. There is therefore a need to re-examine and possibly reform the mechanisms governing the allocation of public resources designed to support individuals' efforts to improve their standard of living.