Punctual or aperiodic

The price readings were collected by the network of INSEE price investigators throughout the month of March 2010.

In Metropolitan France, the consumer price index (CPI) data were used and further readings were taken both in Metropolitan France and in the DOM, on the one hand for the typical DOM products not surveyed in Metropolitan France (Charrette rum, anthurium....), and on the other for the products that were too heterogeneous to use CPI readings only.

In the DOM, the complementary survey was mainly used, with the readings taken for the monthly index limited to foodstuffs.

In Corsica, the complementary survey only was used.

The survey was conducted on the Metropolitan territory (including Corsica) and these four overseas departments (DOM): Guadeloupe, Martinique, French Guiana and Reunion Island (at the moment of the survey, Mayotte was not yet a DOM).

All types of sales outlets were surveyed, according to their local representativeness. Between 4,000 and 7,000 price readings were taken in each of the overseas departments.

For each product, ten to twenty readings were taken, spread between one to four conurbations.

In Corsica, the number was raised to around 8,000, because it was necessary to add the field of food products as well as certain products not included in the comparison with the DOM, as they were absent or barely representative on these territories.

For mainland France, the number of readings taken as well as the CPI was in the order of 5,000, i.e. approximately a hundred products and around 50 readings per product, spread across 12 conurbations in provincial France and 4 departments of Ile de France.

As for the CPI, the sample was stratified according to three types of criteria: a geographical criterion (around 10 conurbations with more than 2,000 inhabitants in Metropolitan France, and the same in the DOM), the product type (400 product families called "varieties", with the variety as the basic level for collecting and calculating elementary price levels), and the sales outlet type (sample of outlets stratified by type of sale).

Along with these price readings in the field, there were the tariffs collected directly from private or public bodies such as EDF, telecoms operators, the National Sickness Insurance Fund (CNAM), and local public services.

For rents, the results of the INSEE housing survey will be used.