• inequality
• wages
• income
• capital

The work is aimed to analyze the income inequality and to explain the role of capital accumulation and income distribution in the process of economic growth. Income inequality, in fact, has grown in recent decades both in advanced economies and in the developing countries, a growth that has been attributed to a number of factors, such as globalization and market liberalization, the entry of people ,into the labor market, less specialized and the increasing of the bargaining power of those who earn more. In the first two chapters of the work, I expose the theories of Modigliani and Friedman: it starts looking at the life cycle theory, according to which consumers tend to save at a young age and adult part of their income, to be allocated to consumption at the end of their working life, and the Permanent income hypothesis concerning the analysis of the relationship between individual and household income and consumption levels. In the third chapter I summarize the main developments of the distribution of income and wealth, as described in the book of T. Piketty, " Capital in the Twenty-First Century ", while in the fourth it will be presented and discussed some data extrapolated from OECD report, “In It Together: Why Less Inequality Benefits All”, showing the longer-term trends as well as recent developments in income inequality through which inequality affects growth. The analysis of the work, mainly concerns the concentration of personal income. Income from capital assets (or investment income), in fact, have a greater concentration than that of income from work, except for the income received from the categories that rank at the top end of the distribution. For investment income, the main cause of inequality is identified in the hereditary transmission of wealth; for labor income, instead, especially in the last years, the main cause of inequality is found in the growth of salaries of "top managers". This category of "workers" has gradually acquired the power to set their remuneration on the basis of their position of power, often regardless of the actual contribution to the production company. But to prevent the groups that have the highest income and wealth are the only ones to gain prominent positions in society, are necessary, above all, transparency and good statistical surveys in order to monitor more effectively than happens today the dynamics of the income and wealth of different social groups. Only in this way it will be possible to adapt the social policies and the levels of taxation under the actual conditions of a country.