Instituto Brasileiro de Geografia e Estatística

2018

• Technical Note - Weighing structures – Table of code correspondence POF x SNIPC
• Technical Note 03/2018 - Manpower for domestic repair
• Technical Note 02/2018 - Domestic worker
• Technical Note 01/2018 - Geographic coverage (updated on 21/03/2018)

2017

• Technical Note 01/2017 - Airfares

2016

• Technical Note 05/2016 - Health insurance
• Technical Note 04/2016 - São Paulo - Water and sewer bill
• Technical Note 03/2016 - Domestic workers a and manpower
• Technical Note 02/2016 - São Paulo - Water and sewer bill 
• Technical Note 01/2016 - São Paulo - Water and sewer bill 

2015

• Technical Note 02/2015 - Airfares
• Technical Note 01/2015 - São Paulo - Transportation

Previous Years

• Technical Note 05/2014 - Fine Subitem
• Technical Note 04/2014 - São Paulo - Water and Sewer Bill
• Technical Note 03/2014 - Rio de Janeiro - Subway and Train
• Technical Note 02/2014 - São Paulo - Water and Sewer Bill
• Technical Note 01/2014 - Pricing system - Suspension
• Technical Note 04/2013 - Electricity - Pricing system 
• Technical Note 03/2013- Expansion of the geographic coverage of IPCA and INPC
• Technical Note 02/2013 - Airfares
• Technical Note 01/2013 - Health Insurance
• Technical Note 01/2012 - Updating of the Weighting Structures based on POF 2008-2009
• Technical Note 01/2011 - Updating of the Weighting Structures based on POF 2008-2009
• Technical Note 03/2010 - Metrô Rio - Subway Service
• Technical Note 02/2010 - Airfares - Sub-Item: Airplanes
• Technical Note 01/2010 - Electricity
• Technical Note 03/2007 - Landline Telephone - Pulses to minutes - Transition - SNIPC
• Technical Note 02/2007 - Domestic Personnel - Adjustment in the calculation methodology of the sub-item Domestic Personnel in the SNIPC, based on PME
• Technical Note 01/2007 - Calculation methodology of the sub-item Manpower for Household Repair of the SNIPC, based on PME
• Technical Note 01/2006 - Sequence - Update of weighting structures based on POF 2002-2003
• Technical Note 02/2005 - Update of weighting structures based on POF 2002-20035 
• Technical Note 01/2005 - Health Insurance
• Technical Note 01/2004 - Health Insurance
• Technical Note 02/2003 - Domestic Workers
• Technical Note 01/2002 - Landline Telephony
• Technical Note 03/2001 - Electricity - Clarification Notes
• Technical Note 02/2001 - Electricity - Calculation Methodology
• Technical Note 01/2001 - Domestic Workers
• Technical Note 01/2000 - New Motor Vehicles
• Regional Weights
• Transition to Real currency
• Methodological Notes - IPCA/INPC - SNIPC Cruzeiro-Cruzado transition

Methodology for the calculation of inflation of the SNIPC subitems "Domestic Worker" and "Manpower for Domestic Repair" based on information on income of the Continuous PNAD. 

• Methodological Note 01/2018

Source: IBGE, Diretoria de Pesquisas, Coordenação de Índices de Preços.

¹ IBGE - Rendimento Monetário mensal familiar disponível (POF 2008-2009).

² IBGE - População residente urbana (POF 2008-2009).

Seasonal Adjustment of Extended Consumer Price Indexes - IPCA/1998

The methodological update aimed at providing users with instruments that help understand the inflation phenomenon is a relevant aspect in the production of consumer price index. 

In this respect, the issue of seasonal adjustment of series of Consumer Price Indexes produced by the IBGE has been part of a project developed by the Department of Price Indexes - DESIP, the main results of which are now being released. 

The objective of the project is to release seasonally-adjusted Conumer Price Indexes that make it possible to interpret information on inflation, without seasonal influences, at both regional and national levels. 

Seasonal changes are periodic and intra-annual movements caused by climatic or institutional (Easter's, Carnival, etc.) calendars. 

Seasonal products are those which present well-defined cycles of production, consumer nd prices. In summary, there times of the year when their availability in retail markets is reduced, with high prices; sometimes it is excessive, with low prices. 

As a result, there is a combination of a reduced level of consumption and high prices and vice-versa. 

It is worth highlighting that the production and release of seasonally-adjusted series is based on the production of additional statistics that: make it possible to have a bettr understanding of the factors that determine price movements;

guide the decision-making process of economic agents, once it makest it possible to distinguish movements occurred in the year, caused by seasonal phenomena, either long-lasting or trend-related ones; 

help in the establishment of government and sector policies that have the objective of eliminating the influence of seasonal movements by means, for example, of the  import of products and maintenance of regulating stocks; 

enable, together with other indicators, the elaboration of macroeconomic studies. 

It is worth mentioning that the seasonal products identified belong to the following groups: Food and Beverages and Wearing Apparel and have their most significant impacts in the months of January, April and August, approximately. 

It is worth mentioning that the annual results (cumulative in the year) of the two series (original and adjusted) are the same. That is due to the fact that the seasonal adjustment takes place within the year (below the average in some months and above in others), which consequently leads to an annual inflation that is the same as in the original series. 

The results of Seasonally-Adjusted Indexes are obtained from the procedure with X11-ARIMA - Estela B. Dagum of the "Time Series Research anda Analysis Division, Statistics Canadá"- PC version.

The methodology of the adjustment can be found in Seasonal Adjustment of Consumer Price Indexes - IBGE/DESIP/RECON - of May 1996.

The IBGE presents the original and adjusted IPCA series, and provides to users one more analytical instrument that is  fundamental for the interpretatiom of the inflation phenomenon. 

Analysis of the Seasonal Adjustment in the Year 

It is known that a long-lasting process of stabilization of prices leads to the absence of indexation, mainly that based on the previous inflation (inertial). So, variation at inflation level, in the short-term, can be influenced by the impact of external factors such as: rise of agriculturalprices motivated by accidental reasons (draught, floods, etc.), correction of administered prices (public or private) and by seasonal movements, among others. 

The seasonal aspect of consumer price indexes, in retail trade, have a clear behavior throughout the year and can be described as follows: in the first semester of the year, the seasonal aspect contributed to the increase of inflation; in the second semester, the phenomenon is inverted in terms of seasonality, thus contributing to the fall of prices. 

In the first semester, the upward pressure on inflation that comes from the seasonal adjustment is mainly motivated by the in-between period and the subsequent scarcity of agricultural products. This semester, there is also the influence of seasonal movements of some products in the group Wearing Appparel, which can be described as: in the first quarter (end of Febrary until March), the sales of products in summer collections, which are so coomon at this type of the year, lead to a movement of deceleration and/or fall of prices that reduce, to some extent, the pressuer exerted by seasonal agricultural products in the period between harvests; in the second quarter (April/June), the prices of some seasonal products in Wearing Apparel, mainly winter items, which that exert contributions on prices, due to the new winter collections launched. 

That behavior reinforces the impact o the prices of the seasonal phenomenon in the first semester. 

In the second semester of the year, seasonality leads inflation downward. Most seasonal food products have their mais supply concentrated in tjhis semester, except beef, with the period between crops occurs in the second semester. 

Seasonal items of winter Wearing Apparel start in July/August and keed prices reduced until the end of August, the period when most sales take place. 

Summer collections are launched in the beginning of September, but the intensity of price changes (increase) are below those in the launch of winter fashion, as well as the changes (fall) in the prices of food products. 

That behevior enables the seasonal adjustment to contribute to the deceleration/decrease of inflation in the second semester of each year. 

In summary, the prices of seasonal products are igher in the first semester of the year. 

For this reason, the seasonally-adjusted series shows that, in tis period of year, there is also a lower level of inflation in relation to the original series. In the second semester, the opposite takes place. 

The behavior described above reveals one of the characteristics of the seasonal phenomenon: seasonality is an intra-annual phenomenon, which is repeated quite regularly in some months of the year, every year. 

This seasonal behavior is well-known by "policy-makers", market analysts, and consumers. 

Nevertheless, what is relevant to identify is the magnitude of this phenomenon and can check what is really happening in terms of change of relative prices, when the seasonal component is isolated. That enables a more accurate evaluation, for example, of the effectiveness of short-term economic policies, with reference to impacts on the inflation component. 

In this respect, the release of seasonally-adjusted IPCA is intended to fill an important gap in terms of the analysis of the inflation process. 

1. Descriptions

- Summarized description 

The National System of Consumer Price Indexes - SNIPC consists of a combination of processes aimed at the production of consumer price indexes. The objective is to monitor price variation of  group of products and services consumed by families. 

The system encompasses the metropolitan areas of Rio de Janeiro, Porto Alegre, Belo Horizonte, Recife, São Paulo, Belém, Fortaleza, Salvador and Curitiba, besides the Federal DIstrict and the municipality of Goiânia. The national index results from an aggregation of regional indexes relative to one same range of income. 

The monthly indexes come, in general, from the comparison of prices in effect on the 30 (thirty) days in the period of reference and the 30 (thirty) days of the base-period.  The full data collection takes place every period of 30 (thirty) days whch is segmented, without interruptions, into 4 (four) subperiods. Each one of them has about 7 (seven) days with dates defined by the Annual SNIPC Data Collection Calendar.  

In a subperiod there is the collection of a fixed one-fourth of the establishments. That way it is possible to obtain from the system indexes with base and reference periods of 30 (thirty) days at the end of each group of four subperiods. 

The indexes can be obtained for several target-populations once the corresponding weighting structure are available for each range of monthly household income. 

From a time-related point-of-view, besides the monthly indexes, it is possible to calculated the price changes for 2 (two) or more months, based on the time-series produced. 

Ii is worth highlighting that the way the system is arranged leads to several possible ways of calculating the index. The National Consumer Price Indexes available are detailed below: 

National Consumer Price Index - INPC and Extended National Consumer Price Index - IPCA

- Current description

The INPC and the IPCA are calculated on an ongoing and systematic basis for the areas covered by the system.

The target-population of the INPC refers to families living in urban localities of the areas covered by the SNIPC with income ranging between 1 (one) to 6 (six) minimum wages, with a salaried householder; that of the IPCA refers to familie living in urban localities of the areas covered by the  SNIPC with income ranging between 1 (one) and 40 (forty) minimum wages, whatever the source of income.

The following set of basic information is used in the basic survey for each region:

Consumer Expenditure Survey - POF

It was conducted between July 2002 and June 2003. The survey provided the weighting structures for the target-populations. 

Survey of Purchase Places - PLC

It was conducted from May to June 1988. The survey provided the register of survey representatives, on an ongoing basis. 

Survey of Specification of Products and Services - PEPS

Conducted in the period of implementation of each one of the areas for all the products and services present in the weighting structure. 

It provided the list of products and services surveyed, which is permanently updated with the objective of monitoring the market dynamics. 

2. Main variables investigated and Survey units 

The prices obtained are those effectively charged to the consumer for on-demand payment. 

The survey is conducted in commercial establishments, services renderers, hhousing units and public service concessionaires. 

3. Geographic coverage

Metropolitan areas of Rio de Janeiro, Porto Alegre, Belo Horizonte, Recife, São Paulo, Belém, Fortaleza, Salvador e Curitiba, besides the Federal District and the municipality of Goiânia.

4. Frequency

Monthly

5. Methodology

The indexes are calculated for each area. Considering prices collected monthly, in the first step, the estimates of price variation for each products surveyed are obtained.

Those estimates result from the calculation of the simple mean of the prices in places where sample prices are obtained. The prices collected in two consecutive months are used to reach the mean figure. 

By aggregating the relative figures of products by means of the geometric mean it is possible to calculate the price variation for each subitem, which is the smallest aggregation of the index that has an explicit weighting.

Then the Laspeyres is applied in order to obtain all the other levels of aggregation for the structure item, subgrou, group and the overall index for the area. 

The national indexes INPC and IPCA are calculated according to regional results, by means of a weighted arithmetic mean. 

The weighting variable for the INPC is "Urban Resident Population" (Consumer Expenditure Survey - POF - 2002-2003) and that of the IPCA  is "Disposable Household Income" (Consumer Expenditure Survey - POF - 2002-2003).

6. Data collection period

Data collection for the IPCA usually takes place between the 1st and the 30th day of the reference month. 

7. Time gap between the collection and the release of data

About 8 (eight) business days.

8. Start of the survey

January/1979 - Rio de Janeiro;

June/1979 - Porto Alegre, Belo Horizonte and Recife;

January/1980 - São Paulo, Brasília and Belém;

October/1980 - Fortaleza, Salvador and Curitiba;

January/1991 - Goiânia;

The Brazil Series is available for dates from September 1981 on.