This introduction presents the main challenges raised by the economic analysis of the long period, as well as the most recent economic approach called Unified Growth Theory. The introduction also presents the goal of this textbook - to allow all students from economics and the social sciences to have access to Unified Growth Theory, as well as the different parts and chapters of the textbook.

Emphasis on structural change as an essential element of long-run growth in capitalist economies since the Industrial Revolution is a main characteristic of Pasinetti’s scientific work. Technical progress is the main driver of structural change and economic growth.Pasinetti integrates structural change in economic analysis by considering the double-sided nature of technical change and the interaction between the supply side (growing productivity) and the demand side (increasing per-capita income) and the evolving structural dynamics of employment and consumption. The analysis is conducted on the basis of vertically integrated sectors which may differ in the growth rates of productivity and demand. In order to maintain full employment over time, an effective demand condition and a capital accumulation condition must be satisfied. In his modern theoretical analysis of Ricardo’s machinery problem Pasinetti shows that a continuous process of structural change is a precondition to avoid technological unemployment. Furthermore, full employment has to be actively pursued by an economic policy raising effective demand and promoting research and development thus combining the insights of Keynes and Schumpeter.

In the framework of a critical illustration of the contemporary history of economics, this chapter illustrates the development of the neoclassical synthesis, from Hicks to Modigliani; its appropriation of the Phillips curve, some Marshallian varieties of the neoclassical synthesis, the developments of growth theory since Solow’s model, stressing the theoretical limits of these developments. A brief appendix synthetically provides an algebraic representation of these developments, while stressing their limits. A final section surveys the variegated field of development analysis.