How is national income generally defined?

National income is generally defined as the total value of a country's output of goods and services over a specific period. This includes all forms of economic activity, providing a comprehensive indicator of economic performance. It reflects the aggregate income earned by residents of a nation, which encompasses wages, profits, rents, and taxes, minus subsidies.

This definition captures the essence of economic productivity and allows for comparisons over time and between different economies. By considering the total value of output, it offers insights into the overall health and growth of the economy, as well as the standard of living within that country.

The other options do not accurately reflect the concept of national income. For example, counting the total number of businesses does not relate to income measurement but rather to economic structure. The formal accounting concept of Gross Domestic Product (GDP) is closely related but specifically focuses on production within the country's borders and does not account for income earned by residents from abroad. Lastly, relying solely on the sum of individual income taxes collected does not provide a complete picture of national income, as it excludes many forms of income generated in the economy.