The structure and trend of the national income or GDP of a country refers to its composition; and changes in its sectorial contribution to the GDP.
NIGERIAN GROSS DOMESTIC PRODUCT (GDP) 1960, 1975, 1981 & 1992
Source: F.O.S. Lagos
I/National Planning Commission Estimates
The table above shows that in 1960, the GDP of Nigeria was ₦2244.6 million. It rose to ₦14,410.9 million in 1975, ₦70,395.9 in 1981 and ₦98,420 in 1992. The percentage contribution of agriculture to the GDP in 1960 was 63.4%. This was followed by wholesale and retail otherwise known as distribution with 9.1%. These were the major contributors to the GDP in 1960. The Mining and Quarrying sector contributed only an insignificant percentage of 0.9. Agriculture continued as a major contributor to the GDP until the early seventies (1970s), when the relatively unimportant mining and quarrying sector gradually took over from it. The table shows that the percentage contribution of this sector from 0.9% In 1960 to 45.5% In 1975, and fell to 15% and 13.2% in 1981 and 1992 respectively. The increase in the contribution of this sector in the early 1990s was mainly due to the increase in the quantity of crude petroleum produced. This period of tremendous increase was known as the “Oil Boom” period. The increase in investment in other sectors of the economy led to increase in their contribution to the GDP over the years.
The increased revenue generated during the oil boom era was solely responsible for the trend.
The trend changed slightly as Nigeria became affected by the glut in the world market which began in the late 1970s. The reduction in the percentage contribution of some sectors to the GDP declined as the fall in world demand for oil meant a fall in revenue and the money available for further investment and expansion. The oil glut forced the government to rekindle emphasis on the agricultural sector which has been neglected in favour of the mining and quarrying sector, during the oil boom era. This had led to the decline in the contribution of agriculture from 63 4% in 1960 to 23.4% in 1975. The renewed emphasis on this sector led to it showing an upward trend in 1981 and 1992 as can be seen in the above table.