The families were selected on the basis of a stratified random sample, consisting of a housing list reported in the population census of 1980, supplemented with a list of buildings constructed since the census; in other words, housing constituted the unit of selection and the family the unit of observation. The survey used the method of directly interviewing families. The data were gathered by means of a monthly form that examined in detail the expenditure and income of families and a daily diary that was used to obtain the daily expenditure and incomes during one week.
The weights were not adjusted to take into account price changes between the survey period and 1987.
| Major groups | Number of items | Weights | Approximate number of price quotations |
|---|---|---|---|
| Food | 101 | 34.9 | 81 |
| Clothing and footwear | 38 | 5.1 | 34 |
| Rent, fuel and light (1) | 4 | 12.6 | 5 |
| Furniture, furnishings, household equipment and maintenance | 37 | 8.4 | 43 |
| Personal and medical care | 11 | 3.5 | 21 |
| Transport and communications | 10 | 15.1 | 24 |
| Education and recreation | 20 | 11.7 | 41 |
| Other goods and services | 23 | 8.7 | 26 |
| Total | 244 | 100.0 | 275 |
Note: (1) Excluding 109 dwellings throughout Panama City, for which rent quotations are obtained.
It excludes contributions to social insurance and pension funds, insurance associated with specific consumer goods, income tax and other direct taxes. In computing the weights of the index, account is taken of life insurance payments, remittances, gifts and similar disbursements.
Prices are collected each month, except those of rents, maintenance, hairdressers, manicurists, air tickets and insurance companies which are gathered each quarter; those of domestic service and education are collected once a year.
The prices of goods and services, except those at the market, are collected in the first three weeks of each month; market prices are obtained on the Tuesday and Thursday of the second week of the month.
Selling-off prices are not taken into consideration when calculating the index. Sale prices are only included if the items are on sale for several weeks and if they are in good condition and part of the regular stock.
In order to facilitate the collection of prices on the basis of established criteria, there is a manual on the items in question and the specifications required for the work. Of course, it should be taken into account that not all items included in the index need to be so precisely defined.
(a) Direct comparison of prices: The substitute item is more or less of the same quality as the article eliminated, but a different brand. The prices of the two brands are directly compared and, if there is any change in price, this is reflected in the index.
(b) Relative linking: The new item may have the same utility or objective but differ in quality even though the price remains the same. These changes do not occur suddenly, but there is a period when the two items are on the market. Both items are valued at the same time and, when the price of the new item is available for two consecutive periods, the substitute item is linked to the index in such a way that the difference in prices between the two items is not reflected in the index. The price of the substitute item is compared with its price in the previous period, and the relative of this item is applied to the weighted price of the item that has been eliminated.
The price relative of each item is calculated by dividing the average price for the current period by the average price for the previous period.
Estadística Panameña(Panama; March, June, September and December).