The FiLoSoFi device is compiled from the following files:
- The file of the statement of fiscal income (POTE), containing the data relative to taxpayers income declarations. This file lists tax households;
- The local residence tax file (PLFC), from which details of those who have to pay the local residence tax are extracted (TH) and linked with dwellings;
- The file of individuals (Fip) that lists all individual reporting to the tax authorities;
- Social files containing comprehensive data on social benefits paid by the main bodies managing these services (CNAF, CNAV and CCMSA), at family level or beneficiary level.
The reconciliation of Pote and PLFC files allows to establish fiscal households when a given fiscal year coincides with at least one independent income declaration (one, two or more tax households) and the occupation of a dwelling identified for residence tax. The reconciliation of Fip file with social files can reconstruct for each tax household all the perceived social benefits.
The "local residence tax payer" is identified in the same way that the tax household is in the Pote file. There is no unique identifier between fiscal and social files: the reconciliation is made from common information in the files (name, surname, date of birth, municipality of residence, etc.). Once the files have been matched, personal information are not kept.
The file of individuals (Fip) contains personal data on each taxpayer which are useful for pairing with social files. Approximation of fiscal and social files enables to avoid total imputation on social benefits scale, as it was done in RDL. INSEE collects via CCMSA annual amounts of statutory benefits in the pension part and the family part within the agricultural system. For the general scheme, the CNAF provides a comprehensive file of recipients and benefits during the year and the CNAV provides a comprehensive file of benefits paid in December. The annual benefit amounts are then reconstituted by extrapolation, using available information on family composition.
In FiLoSoFi, as in the old RDL device, non-subject to declaration financial incomes are allocated for metropolitan households according to a pattern built from the Household Wealth Surveys (INSEE): a probability of detention and a detention amount are estimated according to various observable households characteristics (income, age, family situation ...) for seven financial products (tax-exempt savings deposits , LEP, youth passbook savings accounts , CEL, PEL, life-insurance and PEA.
The taxes retained to compute the disposable income are: income tax, local residence tax, CSG, CRDS and social levy on income from property.
From 2019, the income tax used to calculate disposable income is the tax on the income of the year.
As in the old device RDL, the household type is built from the age differences between individuals, especially to rebuild couples who are not married or civil partners or cohabitants reported as such to the local residence tax.