Answer
One factor leading income inequality is the increase in human capital. Those with higher incomes are more likely to have additional education and/or training in their work sector (compared to those with lower incomes).
Work Step by Step
Another variable contributing to further wage inequality is the rise in unskilled labour in many countries. With the rise in unskilled labor in other countries (and at lower wage levels), demand for domestic unskilled labor is increasing. Domestic unskilled jobs, in effect, have lower wages (and more wage inequality).
