Final answer:
Investment expenditure refers to spending on new capital goods. There are four categories of investment: producer's durable equipment and software, nonresidential structures, changes in inventories, and residential structures. Businesses are responsible for the first three types of investment, while households conduct the last category.
Step-by-step explanation:
Investment expenditure refers to spending on new capital goods. There are four categories of investment: producer's durable equipment and software, nonresidential structures, changes in inventories, and residential structures. Businesses are responsible for the first three types of investment, while households conduct the last category. These categories help determine the overall investment expenditure in the economy.