Income Distribution Movements: A Case Study of Brazil[1]Jose Carlos PelianoAbstract: An income inequality coefficient is developed which includes explicitly the income and frequency series in the analysis to show the movements of the distribution of income. The algorithm gives additional analytical resources to the analysis and permits improving approaches to social mobility, which includes evaluations of inequality. The coefficient has three parts: income effect, which describes the inequality measured by the income shares of the groups in the income series; frequency effect, which describes the inequality measured by the relative frequencies of the groups in the frequency series, and the interaction effect which measures the effect of the interaction of the two variables (income shares and relative frequencies). Temporal evaluation of the frequency effect may point to the movement (mobility) of individuals or groups from one distribution to another. Income distribution movements in Brazil were reevaluated and the proposed coefficient compared to other indicators.1- Social Mobility and Income DistributionThe issue of social mobility began to emerge and take an independent shape based on the inquiries of social scientists in the course of capitalist transformations occurring in Western countries. The missing piece of information was: how do people entering the labor market fare after a few years?Before that, analyses had generally focused on the functioning of the labor market, the social situation of individuals, workers' incomes and the prevailing income structure. There were, indeed, questions on how to improve income over time, as well as on the more and less frequent occupations in the productive sectors. But social mobility as such was not the focus of sociological or economic studies. That would come later.A few years after the 1929 Great Depression, and re-emerging after World War II in the main Western countries, motivated especially by the appearance of the "American way of life," one of the concerns of social scientists who analyzed the capitalist world of that time was to know if, when, how and how much people could objectively improve their lives. American sociology took the lead with these questions and theories and soon they spread[2].How did an American citizen get a good job, buy a new car, rent or buy a nice house with a garden and backyard, equip it well, with a fridge, radio, record player, floor polisher, electric toaster, lawnmower, among other home appliances, and regularly take a vacation with the whole family?And why did only a few achieve this feat, while the silent majority, the blue-collar workers, were employed in simple occupations, with worse pay, without access to the benefits of white-collar workers? What was the size, then, of social mobility, the privileged class who "rose in life", presented and disseminated by the American media of the time in newspapers, magazines, movies, books and marketing, in relation to all else?The question emerged in the wake of concerns about the profile of income distribution in the U.S., which was scarred by the Great Depression, dragging on for years[3]. Other factors worsened the scenario of inequality, such as massive urbanization resulting from agricultural mechanization, on one hand, and expectations of