High Frequency Phone Survey of Households 2022, Round 1
1-2-3 Survey, phase 1 [hh/123-1]
The World Bank is providing support to countries to help mitigate the spread and impact of the new corona-virus disease (COVID-19). One area of support is for data collection to inform evidence-based policies that may help mitigate the effects of this disease.
To monitor the socio-economic impacts of COVID-19 as well as of the latest tsunami and volcanic eruption in Tonga, several rounds of High Frequency Phone Survey on COVID-19 (HFPS) are planned. The documented dataset refers to the first round of the HFPS of Tonga.
The phone survey was conducted to gather data on the socio-economic impacts of COVID-19 crisis, as well as the Hunga Tonga-Hunga Ha'apai volcanic eruption and tsunami in Tonga. Round 1 interviewed 2,527 households both in urban and rural regions of the country from April 12, 2022, to May 7, 2022. Survey topics included employment and income, food security, coping strategies, access to health services, asset ownership, and preparedness. While these findings are not without their caveats due to the lack of baseline data, constraints of the mobile phone survey methodology, and data quality constraints, they represent the best estimates to date and supplement other data on macroeconomic conditions, exports, firm-level information, etc. to develop an initial picture of the impacts of the crises on the population.
Kind of Data
Sample survey data [ssd]
Unit of Analysis
Version 01: Cleaned, labelled and anonymized version of the Master file.
Dataset distributed by the World Bank Group (WBG).
-HOUSEHOLD: Basic Information, Livelihood, Assets (pre- and post-crises), Food Insecurity, Public Services, Coping Strategies, Preparedness.
pacific-skills, education, training
Urban and rural areas.
All respondents must be at least 18 years of age to undertake the survey.
Producers and sponsors
World Bank Group
Sistemas Integrales Consulting Ltda.
The International Bank for Reconstruction and Development
World Bank Group
World Bank Group
Australian Department of Foreign Affairs and Trade
The Tonga HFPS Round 1 sample was generated through a Random Digit Dialing (RDD) process covering all cell telephone numbers active at the time of the sample selection. The survey was administered by Sistemas Integrales.
The RDD methodology generates virtually all possible telephone numbers in the country under the national telephone numbering plan and then draws a random sample of numbers. This method guarantees full coverage of the population with a phone.
First, a large first-phase sample of cell phone numbers was selected and screened through an automated process to identify the active numbers. Then, a smaller second-phase sample was selected from the active residential numbers identified in the first-phase sample and was delivered to the data collection team to be called by the interviewers. When a cell phone was called, the call answerer was interviewed as long as he or she was 18 years of age or above and knowledgeable about the household activities.
It was initially planned to stratify the sample by island group based on the phone number prefixes. However, this was not feasible given the high internal migration across islands and the atypical assignment of phone number prefixes across islands in Tonga. The sample is overrepresenting urban areas and the population of Tongatapu.
The survey interviewed 2,527 households with an unweighted phone response rate of 31.2%.
Tonga HFPS Round 1 includes only household-level data. The household weighting process involves the following five steps:
1. Calculation of the inclusion probabilities of cell phone numbers.
2. Computation of household design weights.
3. Nonresponse weighting adjustment.
4. Weight calibration.
5. Weight trimming and recalibration.
Adjusted weights of respondent households were calibrated to reflect the country distribution of households by island group, sex, age and educational attainment of the household head, the average household size and the average household's wealth status according to the 2016 Tonga Population Census and the 2019 Tonga Multiple Indicator Cluster Survey (MICS).
Survey methodology literature and experience show that cell phone survey results tend to be biased towards male, younger and more educated individuals than the overall population, and towards poorer households. This is due to both cell phone ownership patterns (coverage bias) and differential response rates (nonresponse bias). Such overrepresentation of male, younger and more educated individuals and better-off households can be compensated via weight calibration adjustment. Among the existing calibration techniques, HFPS Round 1 applied the raking method using the logit distance function. The raking margins were based on 2016 Census household counts by island groups and MICS relative distribution of households by household heads' sex, age, education level, household size, and wealth index based on MICS data.
Dates of Data Collection
Data Collection Mode
Computer Assisted Telephone Interview [cati]
Data Collection Notes
The survey management team of Sistemas Integrales included a Project Director, a Project Manager, a Fieldwork Manager, and a Data Manager. The data collection was implemented over 23 days with a team formed by one local coordinator, 20 interviewers and 3 supervisors. All interviewers worked from home, given the mobility restrictions due to the COVID-19 pandemic. The average interview time was 37 minutes.
Total of 11,175 numbers were contacted out of which 2,520 completed the interview. Not accounting for 3,075 inactive/invalid numbers contacted:
· The (unweighted) response rate is 31.2%
· The cooperation rate is 88.5%
· The completion rate is 98.4%.
Sistemas Integrales Consulting
The questionnaire was developed in both English and Tongan. Sections of the Questionnaire:
1. Interview Information
2. Basic Information
5. Food Insecurity
6. Public Services
7. Coping Strategies
The questionnaire is provided in this documentation.
At the end of data collection, the raw dataset was cleaned by the survey firm and the World Bank team. Data cleaning mainly included formatting, relabeling, and excluding survey monitoring variables (e.g., interview start and end times). Data was edited using the software STATA.
For consistency purposes, all categorical levels were labeled identically across variables, where applicable.
Before being granted access to the dataset, all users must formally agree:
1. To make no copies of any files or portions of files to which s/he is granted access except those authorized by the data depositor.
2. Not to use any technique in an attempt to learn the identity of any person, establishment, or sampling unit not identified on public use data files.
3. To hold in strictest confidence the identification of any establishment or individual that may be inadvertently revealed in any documents or discussion, or analysis. Such inadvertent identification revealed in her/his analysis needs to be immediately brought to the attention of the data depositor.
The dataset has been anonymized and is available as a Public Use Dataset. It is accessible to all for statistical and research purposes only, under the following terms and conditions:
1. The data and other materials will not be redistributed or sold to other individuals, Institutions, or organizations without the written agreement of the World Bank Microdata Library.
2. The data will be used for statistical and scientific research purposes only. They will be used solely for reporting of aggregated information, and not for investigation of specific individuals or organizations,
3. No attempt will be made to re-identify respondents, and no use will be made of the identity of any person or establishment discovered inadvertently. Any such discovery would immediately be reported to the World Bank Microdata Library.
4. No attempt will be made to produce links among datasets provided by the World Bank Microdata Library, or among data from the World Bank Microdata Library and other datasets that could identify individuals or organizations.
5. Any books, articles, conference papers, theses, dissertations, reports, or other publications that employ data obtained from the World Bank Microdata Library will cite the source of data in accordance with the Citation Requirement provided with each dataset.
"Tonga Statistics Department, High Frequency Phone Survey on COVID-19 2022 round 1 (HFPS 2022-W1), Version 01 of the licensed dataset (July 2022), provided by the Pacific Data Hub - Microdata Library. https://microdata.pacificdata.org/index.php/home"
The user of the data acknowledges that the original collector of the data, the authorized distributor of the data, and the relevant funding agency bear no responsibility for use of the data or for interpretations or inferences based upon such uses.
DDI Document ID
Statistics for Development Division
Documentation of the study
Date of Metadata Production
DDI Document version
-Version 01 (September 2022): This is the first attempt at documenting the Round 1 of Tonga's 2022 High Frequency Phone Survey. Done by the Statistics for Development Division in Noumea.