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Understanding Compounding and Financial Calculations

Oct 8, 2024

Lecture Notes on Compounding and Financial Calculations

Introduction to Compounding Periods

  • Annual Rate of Return (R): Always quoted on an annual basis in finance, even if compounded more frequently.
  • Compounding Frequency (m): Represents how often interest is compounded within a year.
    • Examples:
      • m=1: Annual compounding.
      • m=2: Semi-annual.
      • m=3: Quarterly.
      • m=12: Monthly.
      • m=365: Daily.
      • Continuous Compounding: Theoretical concept with constant compounding intervals.

Effective Annual Rate (EAR)

  • Purpose: Compares different financial products with varying compounding frequencies by converting rates to an annual equivalent.
  • Example:
    • Bank A: 12.5% compounded annually.
    • Bank B: 12% compounded monthly (equivalent to a 12.68% effective annual rate).
  • Formula: (EAR = (1 + \frac{R}{m})^m - 1).

Annuities and Perpetuities

Perpetuities

  • Definition: A constant stream of cash flows that last indefinitely.
  • Present Value Formula: (PV = \frac{C}{R}), where C is the cash flow and R is the discount rate.
  • Examples:
    • British Consol Bonds.
    • Preferred Stock.

Growing Perpetuities

  • Definition: Cash flows grow at a constant rate (G).
  • Present Value Formula: (PV = \frac{C}{R-G}).

Annuities

  • Definition: A series of fixed payments made over a specified period.
  • Present Value Formula: Derived from the difference between two perpetuities.
  • Applications: Mortgages, car loans, student loans, bond coupon payments.
  • Example Calculation: Determining how much loan to provide based on fixed car payments.

Future Value of Annuity

  • Purpose: Calculates the accumulated value of regular payments at a future date.
  • Example: Regular savings for a college fund.

Growing Annuities

  • Definition: Annuities where payments grow at a constant rate.
  • Example: Retirement plans with inflation-adjusted payments.

Present Value Analysis in Firm Valuation

  • Concept: The value of a firm is the present value of its expected future cash flows.
  • Challenges: Forecasting cash flow size, timing, and risk.

Using Excel for Financial Calculations

  • Functions:
    • FV: Future Value calculation.
    • PV: Present Value calculation.
    • NPER: Number of periods.
    • PMT: Annuity payments.
    • RATE: Rate required to achieve a target future value.
  • Example: Calculating future value of a college fund using Excel formulas.

Conclusion

  • Understanding of discounting, compounding, and annuities is crucial for financial decision-making and product comparisons.
  • Excel provides powerful tools to easily perform such calculations.