Final answer:
Changes in technology, expectations of near-term economic growth, and business taxation will shift the planned investment function, while an increase in interest rates will cause a decrease in the amount of real planned investment.
Step-by-step explanation:
The question refers to factors that cause a shift in the planned investment function. Let's address each part of the question:
- All of the following will cause the planned investment function to shift except changes in the interest rate. So, a change in technology (technological opportunities), expected profits (expectations about near-term economic growth), and business taxation can lead to shifts in the investment function.
- An increase in the interest rate typically leads to a decrease in the investment function because the cost of borrowing funds increases. Alternatively, a decrease in the interest rate can stimulate investment spending, as borrowing becomes cheaper.
Therefore, in part 3 and 4 of your question, an increase in the interest rate causes a decrease in the amount of real planned investment, as higher interest rates usually reduce investment spending.