Household income and poverty in 2020 Arrondissement of Lannion (223)

A tax household is a household comprising the grouped tax households defined for the income taxation linving isted in the same dwelling (excluding collective housing). Its existence in a given year depends on the simultaneous presence of an income tax return and the occupation of an identified dwelling for local residence tax on furnished accommodatio.

For example, a couple of cohabitants in which each person completes its own income tax return is a single tax household because they are listed in the same dwelling, even though they are two distinct taxpayers in the sense of the income taxation.

Hence, the following are excluded from tax households :

• Households made up of persons who are not fiscally independent (most often, students). These persons are counted in the household where they are declared as dependents (households of their parent(s) in the case of students) ;

• Taxpayers living in collective dwellings (workers' hostels, retirement homes, remand establishments, etc.) ;

• The homeless.

The term tax household refers to all the people included on the same income tax declaration.

There may be several tax households within a single household: for example, an unmarried couple who each fill out their own income tax declaration count as two tax households.

The number of persons in the tax household is obtained by adding up the persons listed on the income declarations of the said household. The term person is used rather than inhabitant to highlight the fact that a person attached in tax terms to a household does not necessarily live in it: they may live elsewhere, as is frequently the case of students (attached to their parents for tax purposes but living in a separate dwelling).

For these particular reasons, the number of persons is not always the same as the population of the household in the population census. Differences can therefore be observed between the numbers from the two sources.

To compare the standards of living of households of different sizes or compositions, we divide the income by the number of consumption units (CU). These are usuallly calculated the following way:

• 1 CU for the first adult in the household,
• 0.5 CU for the other persons aged 14 years or older,
• 0.3 CU for the children under 14 years.

This scale (known as the OCDE scale) takes the economy of scale inside the household. Indeed, the needs of the household do not increase proportionally to its size.

When several people live together, it is not necessary to multiply all the consumer goods (in particular durable consumer goods) by the number of people in order to keep the same standard of living.

Disposable income is the income available to the household for consumption and saving. It includes income from employment net of social security contributions, unemployment benefits, pensions, capital income (real estate and financial) and other social benefits received, net of direct taxes.

The latter include income tax, housing tax, the general social contribution (CSG), the contribution to the reduction of the social debt (CRDS) and other taxes on capital income. It includes part of the balance of inter-household transfers.

The share of taxed households is the percentage of taxable households which pay income tax (IRPP). The tax to be paid for a taxable household corresponds to the total of the taxes to be paid by the tax households included in the household.

The monetary poverty rate corresponds to the proportion of individuals (or households) considered as monetary poor.

If a distribution is ordered, the median divides this distribution into two equal parts.

Thus, for a distribution of wages, 50 % of the wages are below the median and 50 % above it.

If a distribution of salaries, income, turnover, etc. are put in order, deciles are the values that divide that distribution into ten equal parts.

As such, for a distribution of salaries :

• the first decile (generally written D1) is the salary below which 10% of salaries are situated ;
• the ninth decile (generally written D9) is the salary below which 90% of salaries are situated.

The first decile is, in the same respect, the salary above which 90% of salaries are situated; the ninth decile is the salary above which 10% of salaries are situated.

Income inter-decile ratios are used to evidence the disparities (or differences) between the richest and the poorest.