stand out more because households are composed of individuals and families living together, in general with diverse incomes, and each groups averages are more distant from those of the other groups, which ultimately lead to this effect on the average income of the whole group.Two observations draw attention. The income effect is almost the same in magnitude from 2001 to 2011 for individuals, but not for families and households, when the magnitude increases in the period. The frequency effect, in turn, increases for the three units of representation, virtually maintaining the same magnitudes from 2001 to 2011.This means that the decrease of P in the period, in the case of individuals, is due solely to the frequency effect, and in the case of families and households, to both effects simultaneously. The frequency effect for individuals brought workers who receive little or nothing up to slightly higher income brackets. Individuals move up the scale to the range of 3-5 times the minimum wage, families and households a step further, to the range of 5 to 10 minimum wages. These movements can be seen in tables 9, 10 and 11 by percentage magnitudes.The income effect in the case of families and households helped the relative incomes (average income of each group i divided by the total average income) of workers closer to the base of the distribution to come closer to those further up the income scale, reducing somewhat and proportionally the distance between them. This effect may be, however, strongly associated with the composition of families and households, as mentioned in the paragraphs above.Thus, there remains only the frequency effect as the main factor that clearly helped reduce income inequality from 2001 to 2011, for individuals, families and households. This result proves nothing more, nothing less, than the existence of a hidden rigidity of behavior and performance in the labor market, which usually allows proportionately more only the entry of new workers around the base of income distributions in the market, while at the same time, and mainly, it operates to limit the rise of groups in occupational structures and income scales.This perennial bottleneck of employment, work and income opportunities[36], as already mentioned above, not only hinders a continuous reduction of inequality, which only occurs marginally and specifically, but also always reproduces the same pattern of differentiation of income and occupation between individuals, families and households.The great engine of production and reproduction of this greater hierarchization of the market in income scales and occupational structures is due to the intrinsic functioning of the market under the capitalist system of production and distribution. Workers adjust to it in an attempt to be always trained, experienced and competent to be able to start and remain working, i.e. at the service of the market.The novelty of this movement of income inequality reduction from 2001 to 2011 in Brazil was the strengthening of population groups, whether individuals, families or households, belonging to the intermediate income brackets in the respective distributions. The so-called middle class gained a largest number of participants, particularly groups earning 2-3 and 3-5 minimum