Edexcel IGCSE Geography 复习笔记 4.1.1 Classification of Economic Sectors & Employment

• An economic activity is the producing, purchase or selling of goods and services
• Economic activities can be grouped into four sectors:
  • Primary
  • Secondary
  • Tertiary
  • Quaternary

• Economic sectors are an indicator of a country's economic development using either:
  • The amount each sector contributes to the Gross Domestic Product (GDP)
  • The percentage of the population they employ
• The proportions of each economic sector GDP and employment changes over time:
  • In the pre-industrial period, the primary sector dominates with steady increases in the secondary and tertiary sectors
  • As countries develop the reliance on the primary sector for GDP and employment rapidly decreases
  • During the industrial period the amount of GDP and employment in the secondary sector increases to become dominant and then decreases. The primary sector continues to decrease and tertiary sector increases
  • In the post-industrial phase, the tertiary and quaternary sectors increase whilst the secondary and primary sectors decrease.
  • The tertiary sector dominates employment and GDP in the post-industrial period

The Clark-Fisher Model

Causes of Changes Over Time

• There are a number of reasons for the change in percentages employed in each sector:
  • Increasing mechanisation in agriculture led to a decrease in the jobs available
  • People moved to urban areas to find jobs in secondary and tertiary sectors
  • Increasing mechanisation and global changes led to a decrease in secondary employment in some countries
  • Technological improvements have led to an increase in tertiary and quaternary employment