The classification of economic activities into Primary, Secondary and Tertiary is useful on account of the information it provides on how and where the people of a country are employed.
Also, this helps in ascertaining as to which sector of economic activity contributes more or less to the country’s GDP and per capital income.
If the Tertiary sector is developing much faster than the Primary sector, it implies that agriculture is depleting and the government must take measures to rectify this.
The knowledge that the agricultural profession is becoming unpopular or regressive can only come if we know which sector it belongs to.
Hence, it is necessary to classify economic activities into these three sectors for smooth economic administration and development.