(2018) Ankèt fanmi sou povrete ak katastwòf, Okap: nòt teknik
Rezime — Dispozitif ankèt fanmi sou povrete ak katastwòf nan Okap: sa ankèt la mande, kijan yo tire echantiyon an ak ki rezèv itilizatè yo dwe konnen sou done yo. Seri DPHS la lye povrete fanmi yo dirèkteman ak ekspozisyon yo devan katastwòf, olye pou l dedwi youn nan lòt.
Teks Konple Dokiman an
Teks ki soti nan dokiman orijinal la pou endeksasyon.
Cap-Haïtien, Haiti
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Disaster Poverty Household Survey— Cap-Haïtien, Haiti
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Overview
Content of this document: This document provides information about the Disaster Poverty
Household Survey (DPHS). It describes the DPHS series, the survey and sampling design
and the questionnaire used, and it discusses some data considerations, including outlier
treatment and anonymization process.
Objective of the survey: The DPHS is designed to collect information that can be used to
assess the relationship between disasters (exposure, vulnerability, and capacity to recover)
and poverty in the urban environment. The data can be used to explore policy-relevant
research topics related to climate change adaptation, urbanization, urban poverty, and more.
Content of the data: DPHS data contains information on household characteristics,
household expenditure, living conditions and household experience with disasters. Household
characteristics include household size and member level information on religion, education
and labor. Household expenditure is collected using the Survey of Well-being via Instant and
Frequent Tracking (SWIFT) methodology, which estimates household poverty based on
household characteristics which are highly correlated with household wellbeing. Information
on living conditions covers housing quality, asset ownership, access to services and jobs, rent
and housing costs and tenure arrangements. Information on experiences with disasters
includes direct and indirect impacts of historic disasters on household assets, education,
health and labor access, as well as impacts on public services. There is also information on
coping behaviors and perception of risk of future exposure. The DPHS can be customized to
collect information on different disasters. So far, it has mainly focused on the impacts of urban
flooding.
Cap-Haïtien application: The DPHS in Cap-Haïtien was conducted in October and
November 2018 in the metropolitan area of the city. The focus of the data collection was to
capture information on exposure to flooding in Cap-Haïtien as well as household preparedness
including access to early warning systems and the use of coping strategies.
The Poverty and Equity Global Practice designed, conducted, and managed the project in
coordination with Global Practice of Urban, Resilience, and Land (GPURL). The Global Facility
for Disaster Reduction and Recovery (GFDRR) financed the project. The Interuniversity
Institute for Research and Development (INURED) carried out the data collection under World
Bank supervision. The municipality of Cap-Haïtien also supported data collection.
Data files and other resources
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Disaster Poverty Household Survey— Cap-Haïtien, Haiti
•
DPHS_CapHaitienHaiti_Data_2018: DPHS data in STATA database format (labels in
English)
•
DPHS_CapHaitienHaiti_SWIFT: SWIFT (household expenditure) data in STATA
database format
•
DPHS_CapHaitienHaiti_Questionnaire: Questionnaire for the DPHS data in excel (in
French)
Citation requirements:
The World Bank. Disaster Poverty Household Survey (DPHS), Cap-Haïtien, Haiti 2018.
Dataset downloaded from microdata.worldbank.org on [date].
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The survey
2.1
Description
Name of the study: Disaster Poverty Household Survey, Cap-Haïtien, Haiti
Geographical coverage: Metropolitan area of Cap-Haïtien
Number of observations: 588 households
Date of the survey: October and November 2018
Primary Investigators: Sering Touray (World Bank), Emilie Perge (World Bank)
Collaborators: GFDRR, Poverty Global Practice and GPURL from the World Bank, and
INURED
Funding: GFDRR
Related reports: Touray and Perge (2020)
2.2
Sampling design
A stratified two-stage sampling strategy was applied to ensure the representativeness of the
survey results. The sampling frame was constructed using the consumption aggregates from
the 2012 Enquête sur les Conditions de Vie des Ménages après le Séisme (ECVMAS)
collected by the Institut Haïtien de Statistique et d'Informatique (IHSI). The first stage identifies
all applicable Primary Sampling Units (PSUs); and the second stage selects households within
selected PSUs.
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Disaster Poverty Household Survey— Cap-Haïtien, Haiti
PSUs are categorized based on two spatial criteria: location the project area and location in
areas with high flood risk. The project area in Cap-Haïtien refers to the areas benefiting from
the Municipal Development and Urban Resilience project (MDUR, P155201). The high-risk
areas are identified based on hazard maps and refer to areas with ‘moderate to high/strong’
and ‘strong to very strong’ risks of floods (Guillande, 2015). Based on these two criteria, four
strata are constructed: project areas with high/moderate risk of floods; project areas with
low/no risk of floods; non-project areas with high/moderate risk of floods; and non-project
Areas with low/no risk of floods.
To calculate the probability of selection of households, WorldPop data is used to assign
number of households per PSU. In the second stage, a listing of all households within a given
PSU is conducted to determine the probability of household selection. By design, 120 PSUs
were surveyed and 5 households per PSU were selected.
Weights are applied to ensure that the estimates obtained from the survey data are
representative of the population of interest.
Figure 1: Sampling frame Cap-Haïtien
Source: Touray and Perge (2020, pp. 29)
3 Questionnaire modules
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Disaster Poverty Household Survey— Cap-Haïtien, Haiti
The questionnaire contains twenty modules with questions at the household and individual
level. The questionnaire is only available in French1.
At the household level, questions include housing characteristics, tenure status, and asset
ownership. At the individual level, there are questions on education, employment, and
unemployment. Additionally, questions on the ownership, use, and coverage of mobile phones
are asked to the household head.
Questions on flooding impact, recovery and coping are asked at the household level. They
include questions about the experience with frequent floods and perception of risk to future
flooding. Impacts of flooding on housing, assets, consumption, access to public services and
transport, work, education, and health are asked. Finally, questions on cooping strategy and
awareness of emergency warning systems are also added.
4 Data considerations
4.1 Anonymization of the dataset
Protecting the privacy of survey respondents is of the outmost importance to the World Bank.
To make sure the data cannot be used to identify individual households in the dataset, a
technique of statistical disclosure control (SDC), as described in Benschop et al. (2021), was
applied. It helped identify variables that included unique information about households. After
identifying the high-risk variables, necessary adjustments were made to make sure the SDC
analysis provided satisfactory results, i.e., low risk of re-identification. Results can be shared
upon request. The following data editing was done for anonymization purpose:
• Precise location data, such as GPS coordinates, were dropped
• Identifying information, such as name and phone numbers were dropped
• Categories for type of dwelling were reduced from 7 to 4.
4.2 Outlier treatment
Continuous variables may present some measurement errors. A technique of outlier treatment
is recommended. Some of these variables are:
• k5: How long did it take to make reparations?
• k6: How much was the cost of reparations?
An established method to identify outliers is to tag the observations that deviate from the mean
1 However, the variable and value labels in the dataset are in English.
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Disaster Poverty Household Survey— Cap-Haïtien, Haiti
by a set number of standard deviations. Three standard deviations are commonly used. Figure
2 includes STATA code that can be used to identify outliers2. Outliers can then be removed or
replaced, using different methods.
Figure 2: Codes for the identification of outliers for the variable k6 (reparations costs)
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SWIFT Methodology
Household consumption data are costly to collect and significantly increases the duration of
interviews. Beyond budgetary and data processing issues, it also reduces the quality of the
data by reducing the space available for the other questions in the survey and by increasing
the risk of survey fatigue of respondents. To avoid these issues, the survey adopted the
SWIFT approach to estimate household expenditures and poverty rates. The SWIFT
methodology collects household data using a short list of questions that can be integrated into
the questionnaire and computes an estimated household income (or consumption
expenditure) based on non-monetary variables that are highly correlated with poverty. SWIFT
uses survey-to-survey imputation based on official household data and produces estimates
comparable to official data. More details on SWIFT are provided in Yoshida et al. (2021).
The data on expenditure are in this dataset: DPHS_CapHaitienHaiti_SWIFT. The DPHS_
CapHaitienHaiti_SWIFT can be matched with the DPHS_CapHaitienHaiti_Data_2018 using
the key variable hhid.
22 Additional checks may be conducted to analyze the presence of outliers. The technique in Figure 1
assumes that the distribution of the variable is normal. This may not be the case, even after using a
logarithmic transformation. Other transformations and for which kinds of variables to use them are
explained in Ravallion (2017). Outliers may influence the mean and the median of the distribution.
More robust methods of outlier treatment may be necessary, for instance, the median absolute
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Disaster Poverty Household Survey— Cap-Haïtien, Haiti
References
BELOTTI, F., G., VECCHI, G., AND MANCINI (2021): “OUTDETECT: Stata module to perform
outlier detection and diagnostics for welfare analysts,”
Statistical Software Components
S458932, Boston College Department of Economics.
BENSCHOP, T. AND WELCH, M. (n.d.): “Statistical Disclosure Control for Microdata: A
Practice Guide”, Retrieved 30 March 2022, from https://sdcpractice.readthedocs.io/en/latest/
GUILLANDE, R., (2015), Caractérisation et cartographie du risque inondation et de
submersion marine sur l’agglomération du Cap-Haïtien, rapport SIGNALERTl n° rep-CIAT –
04-15-001v3,
April
2015
retrieved
05/16/2022
at
http://ciat.gouv.ht/sites/default/files/docs/Rep-FINAL-CIATLIDAR-04.15.001V3.pdf
RAVALLION, M. (2017): “A concave log-like transformation allowing non-positive values,”
Economics Letters, 161, 130-132.
ROUSSEEUW, P. J., CROUX, C. (1993): “Alternatives to the median absolute deviation,”
Journal of the American Statistical association, 88(424), 1273-1283.
TOURAY,S.; PERGE,E. B., 2020, Poverty and Floods in Cap-Haïtien (English). Washington,
D.C. : World Bank Group.
YOSHIDA, N., X. CHEN, S. TAKAMATSU, K. YOSHIMURA, S. MALGIOGLIO, S.
SHIVAKUMARAN, K. ZHANG, D. ARON. (2021): “The Concept and Empirical Evidence of
SWIFT Methodology,” The World Bank. Mimeo.
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