This book studies the relationships between aggregate demand, inequality and instability. It extends the traditional approach by introducing wealth and inequality into a dynamic macroeconomic model. Furthermore, it examines the role that debt and financial instability can play in turbulent times such as the Great Recession and its aftermath. Unlike Piketty, the author analyses the relationships between instability and inequality, and the feedbacks from the latter to the former, in a system approach where real and monetary factors interact to generate complex patterns.