social overhead capital as it is rarely profitable, it has a long gestation period, and the pay-offs accrue to all economic sectors, not primarily to the investing entity; thus the private sector is not interested in playing a major role in its development. All these changes effectively prepare the way for "take-off" only if there is a basic change in the attitude of society towards risk-taking, changes in the working environment, and openness to change in social and political organizations and structures. According to Rostow, the preconditions to take-off begins from an external intervention by more developed and advanced societies, which "set in motion ideas and sentiments which initiated the process by which a modern alternative to the traditional society was constructed out of the old culture." The pre-conditions of take-off closely track the historic stages of the (initially) British Industrial Revolution. Referring to the graph of savings and investment, notably, there is a steep increase in the rate of savings and investment from the stage of "Pre Take-off" till "Drive to Maturity:" then, following that stage, the growth rate of savings and investment moderates. This initial and accelerating steep increase in savings and investment is a pre-condition for the economy to reach the "Take-off" stage and far beyond. The take-off This stage is characterized by dynamic economic growth. As Rostow suggests, all is premised on a sharp stimulus (or multiple stimuli) that is/are any or all of economic, political and technological change. The main feature of this stage is rapid, self-sustained growth. Take-off occurs when sector led growth becomes common and society is driven more by economic processes than traditions. At this point, the norms of economic growth are well established and growth becomes a nation's "second nature" and a shared goal. In discussing the take-off, Rostow is noted to have adopted the term "transition", which describes the process of a traditional economy becoming a modern one. After take-off, a country will generally take as long as fifty to one hundred years to reach the mature stage according to the model, as occurred in countries that participated in the Industrial Revolution and were established as such when Rostow developed his ideas in the 1950s. Per Rostow there are three main requirements for take-off:1. The rate of productive investment should rise from approximately 5% to over 10% of national income or net national product2. The development of one or more