Discrete Dynamical Systems (Springer, 2010)

This book provides an introduction to discrete dynamical systems—a framework of analysis commonly used in the fields of biology, demography, ecology, economics, engineering, finance, and physics. The book characterizes the fundamental factors that govern the qualitative and quantitative trajectories of a variety of deterministic, discrete dynamical systems, providing solution methods for systems that can be solved analytically and methods of qualitative analysis for systems that do not permit or necessitate an explicit solution. The analysis focuses initially on the characterization of the factors the govern the evolution of state variables in the elementary context of one-dimensional, first-order, linear, autonomous systems. The fundamental insights about the forces that affect the evolution of these elementary systems are subsequently generalized, and the determinants of the trajectory of multi-dimensional, nonlinear, higher-order, non-autonomous dynamical systems are established.

Unified Growth Theory (Princeton University Press, 2011)

Backdrop

Throughout most of human existence, economic growth has been all but absent across the globe. But two centuries ago, some regions of the world began to emerge from this epoch of economic stagnation into a period of sustained economic growth, profoundly altering the level and distribution of wealth and health around the world. In his book Unified Growth Theory, Galor provides a global theory explaining what has triggered this remarkable transformation in human history.

Synopsis

Unified Growth Theory is the first theory that sheds light on the determinants of the process of development since the emergence of Homo sapiens. Galor, who founded the field of unified growth theory, identifies the historical and prehistorical forces behind the differential transition timing from stagnation to growth and the emergence of income disparity around the world. He unveils the mechanisms that have trapped the world economy in millennia of near-stagnation but ultimately has induced the remarkable transition to an era of sustained economic growth characterized by vast inequality across countries and regions. Unified Growth Theory suggests that during most of human existence, technological progress was counterbalanced by population growth and living standards were near subsistence across time and space. However, the reinforcing interaction between the rate of technological progress and the size and composition of the population has gradually increased the pace of technological progress, enhancing the importance of education in the ability of individuals to adapt to the changing technological environment. The rise in the allocation of resources towards education triggered reductions in fertility rates, enabling economies to divert a larger share of the fruits of technological progress to the growth of income per capita, rather than towards the growth of population, paving the way for the emergence of sustained economic growth. The theory further suggests that variations in biogeographical characteristics, as well as cultural and institutional characteristics, have generated a differential pace of transition from stagnation to growth across countries and consequently divergence in their income per capita over the past two centuries.

Reception

Robert Solow described Galor's project as "breathtakingly ambitious". He added that "Galor proposes a fairly simple, intensely human-capital-oriented model that will accommodate the millennia of Malthusian near-stagnation, the Industrial Revolution and its aftermath of rapid growth, the accompanying demographic transition, and the emergence of modern human-capital-based growth. And the model is supposed to generate endogenously the transitions from one era to the next. The resulting book is a powerful mixture of fact, theory, and interpretation."^[6]

According to Daron Acemoglu, "Unified Growth Theory is a work of unusual ambition" that "will inspire, motivate, and challenge economists."

Steven N. Durlauf declared that "Unified Growth Theory is Big Science at its best. It grapples with some of the broadest questions in social science, integrating state-of-the-art economic theory with a rich exploration of a wide range of empirical evidence." He considers that Galor's ideas "will have a lasting effect on economics."

The Journey of Humanity: The Origins of Growth and Inequality (Penguin Random House, 2022)

In The Journey of Humanity, Galor wrote a book which wraps his life's studies into one volume, this time intended for a popular audience.^[7][8]