Column 1 of the table shows different investment amounts in a small country. Column 2 shows the expected rate of return made by business firms on a marginal investment, at the different investment amounts. Column 3 shows the rate of interest required to induce savers to supply the different investment amounts.
Marginal Interest Rate Needed
Investment Rate of Return to Induce Supply of Savings
(in $billions) (percent) (percent)
1 15 7.5
2 14 8.0
3 13 8.5
4 12 9.0
5 11 9.5
6 10 10.0
7 9 10.5
8 8 11.0
9 7 11.5
10 6 12.0
a) Draw a diagram showing the supply and demand for investment funds, and the equilibrium interest rate and quantity.
b) Suppose a usury law restricts interest rates to a maximum of 8 percent. What amount of investment will be made?
c) Who is helped and who is hurt by the usury law?