We can be pretty sure we’ll need to repeat the key phrase “economic inequality” in ensuing paragraphs or substitute variations like “inequality,” “economic stratification” or “the disparity between rich and poor,” to remind readers of our central idea. 

Ultimately, though, hitting upon the right way to link our ideas can be one of the most satisfying moments in the writing process. Everything falls into place. When we do manage to clarify that connection, we can relax and readers can relax as they follow the argument’s flow from one point to the next.