Introduction

In the theory of economic growth, we are concerned with the analysis of those economic factors which crucially determine the process of growth for a national economy. Our primary interest is in the mechanisms by which aggregate variables such as national income, aggregate stock of capital, and others are interrelated and in how they change as time passes. Since Harrod (1948) first laid down the fundamental theorems for a dynamic economics, we have seen the emergence of an increasing number of aggregate growth models to clarify and extend these theorems, as aptly described in Hahn and Matthews's (1964) survey article. These growth models, however, have been mostly built upon premises directly involving aggregate variables, without specifying the postulates which govern the behavior of individual units comprising the national economy. In particular, the specifications of aggregate savings are seldom based upon analysis of individual behavior concerning savings and consumption; instead, they have been merely hypothesized in terms of historical and statistical observations. Similarly, the aggregative behavior of investment has been either entirely neglected, as has been typically the case with the so-called neoclassical models, or it has been postulated in terms of somewhat ad hoc relations involving market rate of interest, rate of profit, and other variables.

In the present paper, I should like to pay closer attention to the behavior of individual units concerning consumption, saving, and investment, and to build a formal model of economic growth for which the aggregate variables are described in terms of these microeconomic analyses.