Note d'ouvrage - Nicolas Hatzfeld

New Theories of Growth

After a framework built on Robinson's metaphor, the book opens onto two chapters which contextualize the new theories of growth. The first chapter presents figures describing the importance and historic phases of growth, the roles of labour and capital factors and that of technology. The second chapter reviews the principal traditional theories of growth, and then the neo- classical image, to which the new theories of growth are often contrasted. Then come the two principal chapters.

The theories of endogenous growth do not consider growth as an exogenous given, but as an economic phenomenon. For them, the rate of return on capital does not decrease with the growth of the capital mass. Sources of growth are diverse (physical capital, technology, individuals and their knowledge) and interdependent. There are major consequences: hence poor countries can never catch up developed countries by endogenous growth, and history plays an important role, through the weight of initial conditions and shocks on the trajectory of an economy.

The driving role of technical progress is generally accepted. But theories of endogenous growth integrate technical progress itself into economic activity. It transforms the other factors (markets . . . ) and dynamizes human capital (knowledge). It is its nature as a partially public good which makes knowledge an engine of growth. Technical progress follows a complex dynamic which Schumpeter started to analyze; this analysis is extended by notions of improvement potential, complementarity of technolgies in systems, learning by doing. These theories are partially confirmed by historians and statisticians.

The theories give a renewed economic role to the State: economic policy influences the rate of growth, and not simply the level of production. The State has a role to play in the financing or protection of research, through education. Some research, which reveals inequality as damaging to growth, justifies education as an intervention to reduce inequalities. Others make the connection between private productivity and public capital. For some, the State has to coordinate private agents.

A series of thematic frameworks completes the authors' discussion, either presenting certain models in more detail, or developing certain problems further (overall productivity, endogenous growth and human capital, multiple equilibria, issues of development, growth and financial institutions, growth and inequalities).

In relation to debates on growth, the responses of the new theories of growth, less definite than those of the past, can be summarized as follows: "growth is: long term, doubtless; stable, in part; spontaneously optimal, no". Their procedures recognize the limits of a strictly economic approach to growth, and call for the recognition of institutional factors, such as theories of regulation or conventions. Moreover, they rely heavily on history. In this, they fit in with our own research programme.