Introduction to Small Area Estimation Techniques: A Practical Guide for National Statistics Offices

INTRODUCTION TO SMALL AREA ESTIMATION TECHNIQUES

A Practical Guide for National Statistics Offices

MAY 2020

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ISBN 978-92-9262-222-0 (print); 978-92-9262-223-7 (electronic); 978-92-9262-224-4 (ebook)

Publication Stock No. TIM200160-2

DOI: http://dx.doi.org/10.22617/TIM200160-2

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CONTENTS

TABLES, FIGURES, AND BOXES

FOREWORD

From 2000 to 2015, the Millennium Development Goals (MDGs) influenced global development strategies by setting concrete, time-specific, and measurable targets.

By 2015, the MDGs had achieved substantial progress in poverty reduction and other areas of socio-economic development. In education and health, for instance, the number of out-of-school children of primary school age and the mortality rate for children aged under 5 years had decreased since 1990. Although data for the MDGs generated intercountry comparisons across various social and economic metrics, the absence of granular data meant that they fell short in showing how disparities within each country differed over time. This offered scarce empirical evidence on which sector of a country’s population advanced or trailed behind in relation to the MDGs, and provided insufficient data to inform the development of appropriate programs for vulnerable segments of the population. To address this concern, the 2030 Sustainable Development Agenda pledged that no one will be left behind, and called for more granular data by measuring specific Sustainable Development Goal (SDG) indicators for various clusters of the population (i.e., based on income level, ethnicity, geographic area and other groups relevant to the national context).

Many techniques can generate granular-level SDG data, and each strategy requires different levels of accuracy and data specifications. For survey-based estimates, data granularity implies that the survey sufficiently represents samples from each subgroup of the population. However, most national statistics offices (NSOs) in developing nations are resource-constrained and may not be able to conduct large enough surveys to generate reliable estimates for various subgroups of the population. In such cases, small area estimation methodologies can provide more reliable granular level estimates by borrowing strength from other data collection vehicles with more comprehensive coverage, thus artificially increasing the survey sample size.

This document serves as a step-by-step guide on how to implement basic small area estimation methods and highlights important considerations when executing each technique. Brief discussions of underlying theories and statistical principles are complemented with practical examples to reinforce the readers’ learning process. Due to increasing popularity of usage of R among development statisticians and researchers, software implementation using R is also demonstrated throughout this guide.

This guide is intended for staff of NSOs who are compiling granular statistics needed for SDG data monitoring. The users of this guide are expected to have knowledge of basic concepts of regression modeling. We hope this guide will enrich the portfolio of analytical tools available to NSOs and contribute to increased availability of detailed frameworks for the disaggregation of SDG data.

Yasuyuki Sawada

Chief Economist and Director General

Economic Research and Regional Cooperation Department

Asian Development Bank

ACKNOWLEDGMENTS

Preparation of Introduction to Small Area Estimation Techniques: A Practical Guide for National Statistics Offices was undertaken by the Statistics and Data Innovation Unit of the Economic Research and Regional Cooperation Department at the Asian Development Bank (ADB) and supported by Knowledge and Support Technical Assistance (KSTA) 9356: Data for Development. Arturo Martinez, Jr. led the publication of this guide under the overall direction of Kaushal Joshi and with technical support from Joseph Bulan, Criselda De Dios, and Iva Sebastian.

ADB acknowledges the valuable contribution of Zita Albacea, who prepared the first draft of this guide, and project team members Mildred Addawe, Joseph Bulan, Ron Lester Durante, Jan Arvin Lapuz, Marymell Martillan, Arturo Martinez Jr., and Katrina Miradora, who finalized the guide. We also thank Jose Ramon Albert, Erniel Barrios and Joseph Ryan Lansangan for technical advice, detailed reviews, and relevant documents that served as references in preparing this guide.

We gratefully acknowledge substantial input from Oarawan Sutthangkul, Budsara Sangaroon, Saowaluck Inbumrung, Sanonoi Buracharoen, Thitiwat Kaew-Amdee, Bunpot Teemuangsong,