A simple chaotic model of economic growth and unemployment

Abstract

The study of natural fluctuations has been of great interest for economists for decades. Although the earliest formal models of business cycles, around the 1950s, were endogenous (Hicks, Kaldor, Goodwin), the dominant strategy during the most of the last century has been to assume model specifications for which the equilibrium is determinate and intrinsically stable, so that in the absence of continuing exogenous shocks the economy would tend toward a steady state growth path. By the early 1980's, however, there was a revival of interest in the hypothesis that aggregate fluctuations might represent an endogenous phenomenon that would persist even in the absence of stochastic shocks to the economy. Some authors began to elaborate models with the objective of showing how the nonlinear internal dynamics of the economy generate complex behaviour that appears to be random, providing excellent fits to the behaviour of economic series. In these models, fluctuations result mainly from high level of impatience, imperfect markets or erroneous foresights of the individuals. The purpose of this paper is to show how complex behaviour can emerge from quite simple economic structures. In particular, when sufficient nonlinearities are present, the interaction of some essential elements of developed economies generates irregular fluctuations endogenously. The elements we will consider as representative of a developed economy are economic growth, sustained by knowledge accumulation, and unemployment.

Desde hace décadas los economistas han mostrado un enorme interés por el estudio de las fluctuaciones. El objetivo de este trabajo es mostrar como modelos económicos sencillos pueden generar fluctuaciones muy complejas. Para ello elaboramos un modelo de crecimiento endógeno con acumulación de capital humano y desempleo. Este último es introducido mediante una dinámica de salarios, en particular una curva de Phillips no lineal. Mostramos cómo la introducción de desequilibrios genera dinámicas más complejas de la que habitualmente obtienen los modelos neoclásicos de crecimiento. La tasa de desempleo y la renta per capita fluctúan a lo largo de ciclos de diferentes periodos, e incluso trayectorias caóticas. En particular, cuanto mayor es el grado de desarrollo de la economía mayor es la posibilidad de obtener dinámicas complejas. Además, en la misma línea que los modelos de negociación de salario, obtenemos que cuanto mayor es el poder de negociación de los trabajadores, menores son la tasa de desempleo y la producción per capita.