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Finance Theory
Foundations of Finance
01Defining Finance and the Financial System02Valuation and Management: The Two Challenges03Stocks, Flows, and the Five Cash-Flow Decisions04Time, Risk, and the Six Principles of Finance05How to Learn Finance: Practice and Study HabitsProblem set0/10Problem set 20/10Practice∞
Present Value
01Information and Price: An Auction and Fannie Mae02Who Pays for the Fannie and Freddie Guarantee?03What Counts as an Asset: Patents, Secrets, Brands04An Asset as a Sequence of Dated Cashflows05The Value Operator and the Cashflow Timeline06Dates as Currencies: Building Net Present Value07Discount Factors: Market Prices for Future Dollars08A Worked Net Present Value and Its Assumptions09The Opportunity Cost of Capital and Present ValueProblem set0/10Problem set 20/10MIT problem set0/5Practice∞
01Does the Currency Change an NPV's Sign?02Moral Hazard and Contagion: Where Bailouts Stop03The NPV Rule at Work, and Choosing the Rate04The Perpetuity: Why Cash Forever Is Worth C/r05Reading the Rate Off a Perpetuity's Price06The Growing Perpetuity, and When Growth Outruns r07Building the Annuity from Two Perpetuities08The Annuity Discount Factor and Mortgage Payments09APR, the Effective Annual Rate, and CompoundingProblem set0/10Problem set 20/10MIT problem set0/13Practice∞

The Growing Perpetuity, and When Growth Outruns r

What happens to C/(r − g) when growth catches the discount rate, and why is the answer not simply a big number?


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Your summary note

    1. 1

      Payments CCC, C(1+g)C(1+g)C(1+g), C(1+g)2C(1+g)^2C(1+g)2 discounted at rrr

      Write out the discounted series for a payment growing at rate ggg, and work the example with a first payment of $100 and ggg of 5%, giving $105 the next year.

    2. 2

      Deriving PV=Cr−g\text{PV} = \frac{C}{r-g}PV=r−gC​

      Multiply the series through by 1+r1+g\frac{1+r}{1+g}1+g1+r​, subtract, reduce to PV=Cr−g\text{PV} = \frac{C}{r-g}PV=r−gC​, and record what subtracting ggg does to the denominator and to the value.

    3. 3

      The condition r>gr > gr>g and its two failure cases

      Set g=rg = rg=r in the series and write down what every term becomes, then record what the closed form returns for g>rg > rg>r and what the underlying series gives instead.

    4. 4

      China's growth as the finite-horizon caveat

      Record China's roughly 10% average growth over the fifteen years to 2008 against 5.0% in 2025 as growth above rrr that lasted a while, plus the formula's later use on bonds and stocks.

    Attempt 1 of 2