Gross domestic investment (GDI) is a measure of the amount of money invested in capital goods and structures within a country's economy during a specific period, typically a year. It includes investments made by private businesses, households, and the government, but excludes investments made abroad.

GDI is an important indicator of the health of an economy, as it reflects the level of investment being made in the production of goods and services, and the potential for future growth. It is also closely linked to productivity, as investments in new equipment and technology can increase the efficiency and output of businesses.

In the industry, GDI is used to measure productivity and efficiency within individual sectors, as well as the overall health of the industry. For instance, if GDI in the manufacturing sector is decreasing, it may indicate a slowdown in production due to a lack of investment in new equipment or technology. Conversely, if GDI in the construction sector is increasing, it may indicate a growing demand for new housing or infrastructure projects.

Governments also use GDI as a key tool in economic planning and policy-making. By tracking changes in GDI over time, policymakers can identify areas of the economy that require support or investment, and adjust policies and regulations accordingly. For example, if GDI in the healthcare sector is decreasing, the government may introduce incentives to encourage more investment in medical research and infrastructure.

Overall, Gross domestic investment is an essential measure for analysts, policymakers, and businesses seeking to understand and predict economic growth and productivity.