Consumer price index Bonaire, St Eustatius and Saba
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What does the survey comprise?
Purpose
The quarterly publication of the price development of goods and services that consumers on the islands of Bonaire, Sint Eustatius and Saba purchase. Together, these three islands make up the Caribbean Netherlands. The price development is shown as a price index: the consumer price index
(CPI).
The annual change in the CPI is an important indicator of inflation. The annual change is calculated as the percentage change in the CPI in the reporting quarter compared to the same quarter a year earlier.
In addition to the quarterly publication of the CPI, CBS publishes from 2025 onwards for Bonaire a flash estimate of price development during a certain quarter at total level. In the second month of a quarter, CBS publishes the estimate based on the first month of the quarter. In the third month, the estimate is made based on the first two months of the quarter. After the end of the quarter, in the fourth month, the regular publication of the CPI follows. The flash estimate is overwritten each time and is not suitable for indexation purposes.
For the time being, the flash estimates are made only for Bonaire. For Sint Eustatius and Saba, the source material is currently insufficient for a flash estimate.
Target population
Consumer goods and services purchased by households on Bonaire, Sint Eustatius and Saba.
Statistical unit
Consumer goods and services.
Research start
2010, flash estimate from 2025 onwards.
Frequency
The CPI is published quarterly for all three islands. The flash estimate for Bonaire is published twice a quarter.
Publication strategy
The last quarter’s price indices are provisional. They become final with the publication of the next quarter. Flash estimates are always provisional and are overwritten.
How is it conducted?
Type of survey
The survey is based on monthly price observation at companies and institutions supplying goods and services to consumers. The monthly price observation is used to calculate average prices per quarter. Based on these average prices, price indices of commodity groups are calculated. The price indices of commodity groups are aggregated to the total consumer price index. For the two consecutive flash estimates for Bonaire, the data of the first and the first two months, respectively, are used.
Observation method
Part of the prices are collected by interviewers in physical outlets. In addition CBS uses written surveys and internet observation.
Reporting units
Retail outlets and centrally collected prices at companies, institutions, associations and governments.
Sample size
On Bonaire, prices of about 600 different goods and services are observed at about 125 outlets. On Saba and Sint Eustatius prices of about 350 goods and services are observed at about 70 outlets.
Control and correction methods
The CBS performs checks for completeness and plausibility of the supplied data. Enquiries are made about possible incorrect or incomplete data. In the absence of price observations (non-response), imputations are made (the required information is estimated from the remaining observations). When a defined product undergoes a change, a correction of the price is applied for any differences in quality between the old and the new version of the product.
Weighting
To determine price changes, a basket of goods and services is compiled. Each good or service in this package has a weight that indicates how important it is in the consumption pattern of the residents of Bonaire, Sint Eustatius and Saba. To determine the weighting factors of the various
goods and services in the CPI at the outset (in 2010), use was made of the consumption expenditure from the Budget Survey of the Netherlands Antilles of 2004/2005. From 2014 onwards, the weightings are based on the budget survey that took place in Bonaire, St Eustatius and Saba in 2013. In 2018, new weights were established for the 2017=100 series, for which the average consumption expenditure of households in 2013 was converted to the price level of 2017. The weights are different for each island and are published.
What is the quality of the outcomes?
Accuracy
The accuracy and representativeness of the CPI is ensured by observing the prices of a large and diverse number of products on a monthly basis at different outlets on all three islands. The accuracy of the price trend by product group is generally lower than the accuracy of the price development of the total consumption basket. The survey response rate is above 90 per cent.
Inaccuracy can arise at several places in the production process:
- the sample of outlet;
- the choice of representative items and the estimation of quality differences;
- errors during price observation;
- the determination of weighting factors;
- by non-response.
Comparability over time
Price movements are measured by including, as far as possible, the prices of items that were observed in two consecutive quarters at the same outlet.
Description of quality strategy
The data are checked for internal consistency and completeness. Where necessary action is taken to verify data. If the data are found to be in agreement, the calculation of price indices takes place and the results are checked and validated. The outcomes are validated by a different employee than by whom the figures were compiled.