THE ZERO SECTOR OF THE ECONOMY. Why this book? The fight against poverty and economic underdevelopment are still bottlenecks today and remain at the heart of the major challenges facing economists, governments and international development institutions. The Scottish economist Colin Clark had the idea of defining three main economic sectors, according to the nature of the industry, namely: the primary, secondary and tertiary sectors. Serges IKIEMI defines the fourth sector of the economy which he calls "the zero sector of the economy": KNOWLEDGE as the basis of economic development. How to develop a country? Serges IKIEMI, brings a singular contribution by evoking the fourth sector of the economy or the zero sector: education, KNOWLEDGE and the transfer of the N.T.I.C. (new techniques of information and communication), which are according to him, the root and the nourishing sap of the economy because the industry of the development it is initially the industry of the knowledge. For Serges IKIEMI, there is no economic development except in the conditions of a mental development. It is a debate for the awakening of consciences.