Extending the model
- Households place savings in financial institutions
- Anything that causes households to be thriftier will prompt them to save more at each interest rate, shifting the supply curve rightward
- Conversely, a decline in thriftiness would shift the supply-of-loanable-funds curve leftward and increase the equilibrium interest rate
- On the demand side, anything that increases the rate of return on potential investments will increase the demand for loanable funds
- A decline in productivity or in the price of the firm’s product would shift the demand curve for loanable funds leftward, reducing the equilibrium interest rate
Time-value of money - A specific amount of money is more valuable to a person the sooner it is obtained
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- Compound interest is the total interest that cumulates over time on money that is placed into an interest-bearing account
- Future value - Amount to which some current amount of money will grow to as interest compounds over time; forward-looking
- Present value - Today’s value of amount of money to be received in the future
- Higher interest rate → Greater future value of specific mount of $
Range of interest rates
- Risk - The greater the chance that the borrower will not repay the loan, the higher the interest rate the lender will charge to compensate for that risk
- Maturity - The time length of a loan or its maturity (when it needs to be paid back) also affects the interest rate
- Loan size - If there are two loans of equal maturity and risk, the interest rate on the smaller of the two loans usually will be higher
- Taxability - Interest on certain state and municipal bonds is exempt from Federal income taxation
Pure rate of interest - Best approximated by the interest paid on long-term, virtually riskless securities such as long-term bonds of the U.S. government (20-year Treasury bonds)
Role of the interest rate
- Lower interest rate → Encourages businesses to borrow more for investment
- Rations available supply of loanable funds to investment projects
- Lower cost of borrowing funds → More R&D spending
Nominal interest rate - The rate of interest expressed in dollars of current value
Real interest rate - Rate of interest expressed in purchasing power—dollars of inflation-adjusted value
Usury laws - Specify a maximum interest rate at which loans can be made
- Non-market rationing
- Gainers + losers
- Inefficiency
Economic profit - What remains after all costs—both explicit and implicit costs, the latter including a normal profit—have been subtracted from a firm’s total revenue
- Explicit costs - Payments made by firm to outsiders
- Implicit costs - The monetary income the firm sacrifices when it uses resources that it owns, rather than supplying those resources to the market
- Normal profit - Minimum payment necessary to retain the current line of production
Sources of economic profit
- Static economy - One in which the basic forces such as resource supplies, technological knowledge, and consumer tastes are constant and unchanging
- Profit linked to dynamic nature of real-world capitalism + accompanying uncertainty
- Risk + profit
- Insurable risks - Avoid losses by paying annual fee to insurance company
- Uninsurable risks - Uncontrollable and unpredictable changes in the demand and supply conditions facing the firm (and hence its revenues and costs)
- Changes in general economic environment
- Changes in economic structure
- Changes in gov’t policy
- Innovations + profit
- Innovations undertaken by entrepreneurs entail uncertainty and the possibility of losses, not just the potential for increased profit
- Some of the economic profit in an innovative economy may be compensation for dealing with the uncertainty of innovation
- Monopoly + profit
- Monopoly power → Reduce business risk
- Sustain firm + economic profit
Functions of profit
- Motivates innovation
- Allocates resource among production
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