What caused economic inequality to rise in the early 1980s even as the economy improved overall?

High interest rates and falling wages of the workers compared to the inflation caused the economic inequality to rise.

Explanation:

In the 1980s US was in a middle of an economic boom but the population was not getting the full benefit of these developments because of the inequality in wages and the way the interest was soaring up  in the booming economy.

The wages did not rise as much as the inflation did and the interest rates and the mortgage rates had also become very high in a short period of time.

This made the poor more poor while it filled the pocket of the rich and it kept making them money and the economy boomed.

it would have to be gasioline