Linear-stages-of-growth model
An early theory of development economics, the linear-stages-of-growth model was first formulated in the 1950s by W. W. Rostow in The Stages of Growth: A Non-Communist Manifesto, following work of Marx and List. This theory modifies Marx's stages theory of development and focuses on the accelerated accumulation of capital, through the utilization of both domestic and international savings as a means of spurring investment, as the primary means of promoting economic growth and, thus, development. The linear-stages-of-growth model posits that there are a series of five consecutive stages of development which all countries must go through during the process of development. These stages are "the traditional society, the pre-conditions for take-off, the take-off, the drive to maturity, and the age of high mass-consumption"Simple versions of the Harrod–Domar model provide a mathematical illustration of the argument that improved capital investment leads to greater economic growth.
Such theories have been criticized for not recognizing that, while necessary, capital accumulation is not a sufficient condition for development. That is to say that this early and simplistic theory failed to account for political, social and institutional obstacles to development. Furthermore, this theory was developed in the early years of the Cold War and was largely derived from the successes of the Marshall Plan. This has led to the major criticism that the theory assumes that the conditions found in developing countries are the same as those found in post-WWII Europe.