Investment and Economic Activity

Read this chapter to examine factors that determine private investment and its link to output within the macroeconomy. Private investment plays an important role in the short run by influencing aggregate demand, and in the long run by influencing the rate of growth of the economy.

14.2 Determinants of Investment


  1. Draw a hypothetical investment demand curve, and explain what it shows about the relationship between investment and the interest rate.
  2. Discuss the factors that can cause an investment demand curve to shift.

We will see in this section that interest rates play a key role in the determination of the desired stock of capital and thus of investment. Because investment is a process through which capital is increased in one period for use in future periods, expectations play an important role in investment as well.

Capital is one factor of production, along with labor and natural resources. A decision to invest is a decision to use more capital in producing goods and services. Factors that affect firms' choices in the mix of capital, labor, and natural resources will affect investment as well.

We will also see in this section that public policy affects investment. Some investment is done by government agencies as they add to the public stock of capital. In addition, the tax and regulatory policies chosen by the public sector can affect the investment choices of private firms and individuals.