Nor are these challenges limited to the poorest Americans. Many middle-class families face comparable difficulties paying for housing and health care, attaining a decent education, and establishing savings. This is the second issue: A weaker middle class means a weaker economy. As recent research by International Monetary Fund economists Michael Kumhof and Romain Rancière suggests, higher inequality creates conditions for economic instability. In contrast, a strong middle class encourages stable, robust consumption, and therefore stable, robust demand for domestic goods and services and sustainable growth.