Unplanned investments and undesirable stock changes do not have any impact on the equilibrium level of income. For this reason, economists are interested in factors that affect planned investments. First one is the interest rate. The second factor that determines the amount of investment is the expected profitability of investment. One of the main driving forces behind new investments is technological change. Another factor that affects investment expenditures is the cost of capital goods and the last one is capacity utilization.