What is the meaning of 'income inequality'? ( what does 'income' mean; that is, how does 'income' differ from 'compensation', 'earnings', or 'wages'?)
How unequal is the distribution of income in the United States?
What are the major labor market factors contributing to income inequality?
How clearly does "quintile analysis" (arranging all households - or families, depending on the data source - by income into 5 'quintiles', each containing an equal number of households but an unequal amount of income) describe the actual levels of inequality in compensation (and indeed well-being) among individuals in society?