The Theory of General Economic Equilibrium book discusses how economies reach a balance where supply meets demand. It covers topics like efficiency, welfare, and international trade. The book explains that when consumer preferences are taken into account, the theory of efficiency is replaced by optimality theory. It also talks about how consumer choices can affect family sizes. The book emphasizes the importance of equilibrium in economics and how quickly an economy can reach a stable state. This resource is helpful for economists and advanced economics students.