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Reproducibility package for Population Thresholds And Classification Stability: Evidence From The World Bank's Small States Classification Rule

2026
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Reference ID
RR_WLD_2026_681
Author(s)
Baran Han
Collections
World Bank Policy Research Working Papers
Metadata
JSON
Created on
Jul 23, 2026
Last modified
Jul 28, 2026
Page views
10
  • Overview
  • Reproducibility Package
  • Description
  • Scope and coverage
  • Disclaimer
  • Access and rights
  • Contacts
  • Information on metadata

    • Overview

    Abstract

    This paper assesses whether the World Bank's ≤1.5 million population threshold for Small States classification corresponds to a meaningful structural break in macroeconomic outcomes. Using cross-country data for Emerging Market and Developing Economies (EMDEs) over 2000–2024, regression and nonparametric evidence consistently show that volatility and trade openness decline smoothly with population size, with no detectible discontinuity around the 1.5 million threshold or any other natural breakpoint. The threshold thus functions as an administrative anchor rather than an empirically grounded breakpoint. Given that population estimates are subject to periodic revision, which may inadvertently trigger reclassification without sustained demographic change, the paper evaluates four implementation rules and recommends an asymmetric persistence requirement.

    Reproducibility Package

    Scripts
    Get Reproducibility Package
    File name
    RR_WLD_2026_681
    Zip package
    RR_WLD_2026_681.zip
    Title
    Reproducibility package for Population Thresholds And Classification Stability: Evidence From The World Bank's Small States Classification Rule
    Date
    2026-07
    Dependencies
    Stata dependencies are listed in the ado folder.
    Instructions
    See README in reproducibility package.
    Notes
    Computational reproducibility verified by Development Impact (DECDI) Analytics team, World Bank.
    Source code repository
    Repository name URI
    Reproducible Research Repository (World Bank) https://reproducibility.worldbank.org
    Software
    Name
    Stata
    Version
    19.5 MP

    Reproducibility

    Technology environment

    Paper exhibits were reproduced on a computer with the following specifications:
    • OS: Windows 11 Enterprise
    • Processor: Intel(R) Xeon(R) Gold 6226R CPU @ 2.90GHz
    • Memory available: 32.0 GB
    Technology requirements

    Runtime: ~20 minutes.
    Reproduction instructions

    To reproduce the findings in this paper, a replicator must:

    1. Update the working directory of the do-file 0.master.do
    2. Run the Package.

    Data

    Datasets
    Name
    World Development Indicators
    Note
    Source: World Bank. Indicators used: Population, total (SP.POP.TOTL); Land area (sq. km) (AG.LND.TOTL.K2); Fuel exports (% of merchandise exports) (TX.VAL.FUEL.ZS.UN); Net barter terms of trade index (2015 = 100) (TT.PRI.MRCH.XD.WD); Trade (% of GDP) (NE.TRD.GNFS.ZS); GDP, PPP (constant 2021 international $) (NY.GDP.MKTP.PP.KD); GDP per capita, PPP (constant 2021 international $) (NY.GDP.PCAP.PP.KD). Access date: Data downloaded by the code on June 10, 2026. File location: "data\wdi_panel.dta".
    Access policy
    Data is publicly available and included in the reproducibility package.
    License
    Creative Commons Attribution 4.0 (CC BY 4.0)
    License URL
    https://datacatalog.worldbank.org/public-licenses
    Data URL
    https://databank.worldbank.org/source/world-development-indicators
    Citation
    World Bank. 2026. "World Development Indicators" [dataset]. World Bank. https://databank.worldbank.org/source/world-development-indicators. Accessed June 11, 2026.
    Name
    World Development Indicators Archives, population vintages
    Note
    Source: World Bank. Indicators used: Population, total (SP.POP.TOTL) for the following vintages: June 28, 2019, July 1, 2020, July 30, 2021, June 30, 2022, June 29, 2023, July 1, 2024, and July 2, 2025 Access date: Data downloaded by the code on June 10, 2026. File location: "data/population/".
    Access policy
    Data is publicly available and included in the reproducibility package.
    License
    Creative Commons Attribution 4.0 (CC BY 4.0)
    License URL
    https://databank.worldbank.org/source/world-development-indicators
    Data URL
    https://datatopics.worldbank.org/world-development-indicators/wdi-archives.html
    Citation
    World Bank. 2026. "World Development Indicators Archives" [dataset]. https://datatopics.worldbank.org/world-development-indicators/wdi-archives.html. Accessed June 2026.
    Name
    Country classification and distance file
    Note
    Source: Authors' compilation. Contains country classification variables, sample restrictions, lending and income group variables, regional identifiers, and distance-from-markets variables. The distance-from-markets variable is extracted from Table 6 of the UNCTAD Least Developed Countries Report 2021 (https://unctad.org/system/files/official-document/ser-rp-2021d10_en.pdf). Access date: June 10, 2026. File location: "data/country_categorization_distance.xlsx”.
    Access policy
    Data is publicly available and included in the reproducibility package.
    Data statement

    All data sources are publicly available and included in the reproducibility package.

    Description

    Output
    Type
    Working Paper
    Title
    Population Thresholds And Classification Stability: Evidence From The World Bank's Small States Classification Rule
    Description
    Policy Research Working Papers (PRWP)
    Authors
    Author Affiliation Email
    Baran Han World Bank bhan3@worldbank.org
    Date of production

    2026-07-17

    Scope and coverage

    Geographic locations
    Location Code
    World WLD
    Topics
    ID Topic Parent topic ID Vocabulary Vocabulary URI
    C12 Hypothesis Testing: General C1 Journal of Economic Literature (JEL)
    C18 Methodological Issues: General C1 Journal of Economic Literature (JEL)
    C23 Panel Data Models • Spatio-temporal Models C2 Journal of Economic Literature (JEL)
    F35 Foreign Aid F3 Journal of Economic Literature (JEL)
    O11 Macroeconomic Analyses of Economic Development O1 Journal of Economic Literature (JEL)

    Disclaimer

    Disclaimer

    The materials in the reproducibility packages are distributed as they were prepared by the staff of the International Bank for Reconstruction and Development/The World Bank. The findings, interpretations, and conclusions expressed in this event do not necessarily reflect the views of the World Bank, the Executive Directors of the World Bank, or the governments they represent. The World Bank does not guarantee the accuracy of the materials included in the reproducibility package.

    Access and rights

    License
    Name URI
    MIT License https://opensource.org/license/mit
    World Bank IGO Rider https://github.com/worldbank/metadata-editor/blob/main/WB-IGO-RIDER.md

    Contacts

    Contacts
    Name Affiliation Email
    Baran Han World Bank bhan3@worldbank.org
    Reproducibility WBG World Bank reproducibility@worldbank.org

    Information on metadata

    Producers
    Name Abbreviation Affiliation Role
    Reproducibility WBG DECDI World Bank - Development Impact Department Verification and preparation of metadata
    Date of Production

    2026-07-17
    Document version

    1
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