|Unit||Index Dec2020=100, SA|
|Source||National Institute of Statistics and Census (INEC)|
For Costa Rica, a monthly consumer price index with COICOP detail. It is a Laspeyres index.
The source writes:
The classification system used for the CPI is a slightly modified national version of COICOP. Although certain sub-components of COICOP have been moved from one major group to another, and the order and composition of some of the major components have been changed, the national version of COICOP can be mapped easily into the international version of COICOP.
All socio-economic strata are represented in the CPI. Excluded from the index’s reference population are groups of more than seven non-related individuals living in the same housing unit.
The CPI is compiled using a mix of urban districts and other blended urban/rural districts where a formidable percent of the population resides and an even high percentage of consumer spending compared to the population as a whole.
The COICOP-based national classification and coding system used for the CPI is composed of 12 Divisions or major groups, 31 sub-groups, 54 classes, 82 sub-classes, 292 articles, and 398 varieties.
Types of prices
Both market basket weights and monthly prices used in the compilation of the CPI are valued at market prices, including sales tax and applicable discounts. Detailed product characteristic data including terms of transactions are included as part of the specifications for monthly price collection.
Timing of price observation
Both the expenditure data from the income and expenditure survey and the price data for the monthly price survey are recorded on an accrual basis. The weights for durable goods in the CPI market basket are based on net purchases (the value of purchases less the value of sales) of these goods, in accordance with international recommendations.
Sources of weights
The list of goods and services included in the CPI market basket and their corresponding index weights were derived from the ENIG that was conducted during a gien 13 month period. This survey covered households from all socio-economic groups in both the urban and rural sectors of the entire country.
Frequency of weight updates
The weights applied to the items in consumption basket are not updated frequently; A new ENIG is planned in the short term.
The basket included a number of items meeting any of the following criteria: 1. Spending on the item in question must represent 0.05 percent or more of the total expenditure reported by the reference households. 1. Item consumed in 5 percent or more of households,
A random sampling method is used, and variables included the branch of activity and variability of the prices for each specific item, to help determine the required number of establishments.
Most of these data are collected through personal visits. All data collected for the CPI are processed and tabulated at the INEC’s facility in San Jose.
Price collection methods
Personal visits using forms designed to gather information at the establishments in the sample, distributed over the course of the month. To determine prices of utilities and other public services, researchers call the offices of the enterprises providing those services, which are verified in the pertinent edition of La Gaceta.
Specifications of each of the items (goods and services) are found in a Specifications Manual, describing the characteristics of the items in question so that price researchers may readily identify the target items.
Computation of lowest level indices
Elementary aggregates are estimated using the geometric means.
The index is compiled using the short-term formulation of the Laspeyres index formula for higher level aggregates.
Alignment of expenditure and base period
Market basket weights derived from expenditure data from the ENIG were updated to the reference base for the CPI
Treatment of missing prices
For temporarily unavailable product specifications/outlets, prices are imputed in one of two ways. If 50 percent of the prices for a product are available, the price for the product/specification/outlet is imputed using the prices of the same product in other outlets. When less than 50 percent of the prices for a product are available, the price is imputed using the price movement all products in the subclass to which the product pertains.
Adjustments for quality differences
In general, only implicit quality adjustments are made. The price for a non-comparable substitute product specification/outlet is left out of the compilation of the index until it is available for two consecutive months. Direct quality adjustments are generally not made except for adjustments in quantities of the product.
Selection of replacement items
When it is known that a particular item is to become permanently unavailable, the item in question must be replaced with a comparable product, with another brand albeit having the same specified characteristics as the previous item.
Introducing new products
New products may only be introduced into the consumption basket in the event that the base of the index is changed, something which happens seldom.
The index only includes the prices of rental housing.
Seasonally adjusted indices
The index undergoes no adjustment to reflect the seasonal behavior of the items included in the index.
For the general index, we have back-extended using IMF data (1974m10 to 1975m12). We have constructed a seasonally adjusted counterpart.
No. The data are considered definitive when first released and are not subject to further revision.