, Wage inequality series also show clear rise of P90/P10 and P50/P10 over 1950-1968, and strong decline over 1968-1983 (see Piketty, This delivers P50 around 70-75% of average throughout postwar period, which is consistent with, pp.670-672, 1956.

, In order to match higher P0-50 share in 1950 (suggested by wealth inequality estimates), the linear adjustment is taken over the 1950-1970 by the tax law, such as the 10% lump-sum deduction for professional expenses of wage earners -up to ceiling, p.20

, We first use upgrade rates due to previous-year-tax deduction. Then, we take into account others kinds of deduction (including lump-sum deductions for wage earners) updating correction factors previously used, We correct this in two steps, applying and updating correction factors used in Piketty, 2001.

, Enquête Revenus Fiscaux was produced jointly by INSEE and the tax administration from 1956 to 1990. These surveys described the socio-demographic structure of approximately 40,000 tax units along with all the information reported in their income tax returns