<P> The three - sector theory is an economic theory which divides economies into three sectors of activity : extraction of raw materials ( primary ) , manufacturing ( secondary ) , and services ( tertiary ) . It was developed by Allan Fisher , Colin Clark and Jean Fourastié . </P>
<P> The three - sector theory is an economic theory which divides economies into three sectors of activity : extraction of raw materials ( primary ) , manufacturing ( secondary ) , and services ( tertiary ) . It was developed by Allan Fisher , Colin Clark and Jean Fourastié . </P>
what are primary secondary and tertiary sectors of economy
what are primary secondary and tertiary sectors of economy
extraction of raw materials ( primary ) manufacturing ( secondary ) services ( tertiary )
extraction of raw materials ( primary ) manufacturing ( secondary ) services ( tertiary )