在1950年代和1960年代，西蒙·库兹涅茨（Simon Kuznets）假设，随着经济的发展，市场力量首先增加，然后减少了社会的总体经济不平等，这一点可以通过库兹涅茨曲线的倒U形来说明。 例如，该假设认为，在经济的早期发展中，已经有资本进行投资的人会增加新的投资机会。 这些新的投资机会意味着那些已经拥有财富的人有机会增加财富。 相反，廉价的农村劳动力涌入城市，使工人阶级的工资下降，从而扩大了收入差距，加剧了经济不平等。
In the 1950s and 1960s, Simon Kuznets assumed that with the development of the economy, market forces first increased and then reduced the overall economic inequality of society. This can be achieved through the Kuznets curve. Inverted U-shaped to illustrate. For example, the hypothesis states that in the early development of the economy, people who already have capital to invest will increase new investment opportunities. These new investment opportunities mean that those who already have wealth have the opportunity to increase their wealth. On the contrary, the influx of cheap rural labor into cities has reduced the wages of the working class, thereby widening the income gap and exacerbating economic inequality.