Investment (I): This refers to spending by firms on capital goods, such as new machinery, buildings, and increases in inventory. It represents money flowing from the financial market into firm

Here are 3 injections in the Circular Flow of Income:

1. Investment (I): This refers to spending by firms on capital goods, such as new machinery, buildings, and increases in inventory. It represents money flowing from the financial market into firms.
2. Government Spending (G): This is the spending by the government on goods and services, including public infrastructure projects, defense, education, and healthcare. It represents money flowing from the government sector into firms and households.
3. Exports (X): This is the spending by foreign residents on domestically produced goods and services. It represents money flowing from the foreign sector into domestic firms.