Putting the gordon equation into practice
The Gordon equation does not use inflation-adjusted numbers. It uses nominal returns/dividends and growth rates. It really says nothing anyone would not already know.  Everyone knows that your total return equals the sum of the income return plus capital gains.   Gordon simply assumes (perfectly validly) that capital gains will be driven by the growth of earnings, and that the dividends paid will likewise increase at the same rate. So he used the 'dividend growth rate' as a proxy for the 'earnings growth rate' or 'capital gains rate'. You cannot use inflation-removed estimates of equity rates of return because those returns do not change with inflation.  If anything they move in opposite directions.  Eg in the 1970's inflation the high market rates caused people to discount equity values at larger rates --- driving their values down -- creating losses.
"Not to detract from the other answers at all (which are each excellent and useful in their own right), but here's my interpretation of the ideas: Equity is the answer to the question ""Where is the value of the company coming from?""  This might include owner stakes, shareholder stock investments, or outside investments.  In the current moment, it can also be defined as ""Equity = X + Current Income - Current Expenses"" (I'll come back to X). This fits into the standard accounting model of ""Assets - Liabilities = Value (Equity)"", where Assets includes not only bank accounts, but also warehouse inventory, raw materials, etc.; Liabilities are debts, loans, shortfalls in inventory, etc.  Both are abstract categories, whereas Income and Expense are hard dollar amounts.  At the end of the year when the books balance, they should all equal out. Equity up until this point has been an abstract concept, and it's not an account in the traditional (gnucash) sense.  However, it's common practice for businesses to close the books once a year, and to consolidate outstanding balances.  When this happens, Equity ceases to be abstract and becomes a hard value: ""How much is the company worth at this moment?"", which has a definite, numeric value. When the books are opened fresh for a new business year, the Current Income and Current Expense amounts are zeroed out.  In this situation, in order for the big equation to equal out: Assets - Liabilities = X + Income - Expeneses the previous net value of the company must be accounted for.  This is where X comes in, the starting (previous year's) equity.  This allows the Assets and Liabilities to be non-zero, while the (current) Income and Expenses are both still zeroed out.  The account which represents X in gnucash is called ""Equity"", and encompasses not only initial investments, but also the net increase & decreases from previous years.  While the name would more accurately be called ""Starting Equity"", the only problem caused by the naming convention is the confusion of the concept Equity (X + Income - Expenses) with the account X, named ""Equity""." This. I'd ask around a bit to find out if more people miss the bowling alley, see if there is interest for a 'reboot'. Also, at the very least you should talk to the current owners about how it is going, what's happening etc. to put some feelers out without expressing direct interest. Maybe they have racked up a hefty debt, who knows. Scope it out a bit.  Be wary of looking at it from a sentimental point of view. You had a great time there, you're not guaranteed to have that again, even with you running it. Running it and visiting it are way different.  You will probably have to do a lot of marketing/publicity stuff for it, so plan accordingly. And what 9ersaur said, you probably need capital, especially if the business has been stagnant. If they serve food, the kitchen may not be up to standards anymore, etc.  If after that you still want to do it, and have a plan, then definitely opt for buying them out directly or over time. You probably do not want the previous owners' emotional attachments getting in the way. (cue gordon ramsay's restaurant makeovers) That said, they may just like what you want to do and support you all the way, who knows.  Good luck! You are comparing a risk-free cost with a risky return. If you can tolerate that level of risk (the ups and downs of the investment) for the chance that you'll come out ahead in the long-run, then sure, you could do that.   So the parameters to your equation would be: If you assume that the risky returns are normally distributed, then you can use normal probability tables to determine what risk level you can tolerate. To put some real numbers to it, take the average S&P 500 return of 10% and standard deviation of 18%.  Using standard normal functions, we can calculate the probability that you earn more than various interest rates: so even with a low 3% interest rate, there's roughly a 1 in 3 chance that you'll actually be worse off (the gains on your investments will be less than the interest you pay).  In any case there's a 3 in 10 chance that your investments will lose money. You absolutely can be put in jail in America for debt... if that debt is to a government or government agency (like a municipal government). If you have unpaid court costs, fines, etc., it's common practice in most municipalities to issue an arrest warrant for those, even if non-payment is due to being indigent. In a lot of cases, even if you show up to explain why you can't pay or make a partial payment on the due date, you'll be arrested and jailed until a judge is available to hear your explanation, if one isn't available right when you go in. What's supposed to happen is that if you're indigent (can't pay), a judge will hear your explanation and, provided it's determined that you're indigent, make adjustments to what you owe (cancel or reduce the amount, extend the due date, setup a payment plan, etc.) and send you on your way. It bears mentioning that even in cases where the system works like it should, there's still a very real chance of being put in jail, which isn't harmless - people can and do lose their jobs while they're sitting in jail waiting to plead indigence to a judge. And of course, what's supposed to happen isn't what always does. The police shootings of the past couple years in Missouri have shone some light in a lot of dark corners down there, where there are, in fact, de-facto debtor prisons in many municipalities.  In addition to civil rights groups filing suit over this in many Missouri municipalities, the US Department of Justice has filed suit against the city of Ferguson over their municipal practices (including their use of the courts and jails to generate municipal revenue). Some forms of private debt (like child support) also fall under this umbrella where an arrest warrant will be issued for failure to pay for any reason, and this was determined to be a factor in the Walter Scott shooting - Walter Scott ran to avoid being put in jail over child support debt, and losing his job while in jail. The New York Times highlighted his case in an article titled: Skip Child Support. Go to Jail. Lose Job. Repeat. Rodney Scott said that he sometimes thought his brother did not do everything he could to catch up, but that Walter seemed to consider it a hopeless cause. He recalled seeing his brother plead to a judge that he just did not make enough money. “He asked the judge, ‘How am I supposed to live?’ ” Mr. Scott said. “And the judge said something like, ‘That’s your problem. You figure it out.’ ” nice work! really enjoyed looking through your website. do you see any possible application of Machine Learning (specifically tensorflow) to this? I was thinking about building a trading bot that uses data from various APIs as a strategy just as an experiment but I'm wondering what your insights are. I am an instructor who teaches Financial Modeling courses to investment bankers in NYC. Looking at the model, I do not see anything wrong with it. There are just too many assumptions. I would rather use the Multiple Value for the Terminal Value calculation, but, it will not make any significant differences. Some more thoughts :  a) The author has used text book method for valuation, but, everyone improvises the text book method, hence, subjective evaluations.   b) Oil and Gas valuation is quite a deep subject and every time we create models, industry experts come and big time change the inputs. We have no indication that the model is tested by industry experts (O&amp;G Operations experts)  c) For matured companies like ARAMCO, I would prefer the DCF model as used and then parb (adjust) using comparables. I do not see that it has been done in the model.  d) In some cases, investment experts would rather use 3 stage DCF model (5 years, next 10 years, next 20 years or so). It makes the model pretty complex, but, provides more accuracy.  e) The revenue taken in the calculation is flat, instead, he should have taken the data from past 10 years and modeled the fluctuations.   f) One of the biggest challenges we have faced in this sector is the accounting method full cost of successful effort. High CAPEX only occurs in one of the methods and depending on the company's maturity level, people may use different methods. More on this method in this link -http://www.investopedia.com/articles/fundamental-analysis/08/oil-gas.asp  I am at wits to understand how the value will be more than 1 Trillion dollars in any case. Maybe this video can explain it better.   I'm sorry, I don't know how else to explain it. I'm not sure if you're getting it. This video looks pretty informative to me. Admittedly I haven't watched the whole thing. I just watch the first few minutes. Maybe a visual demo will help.   http://www.youtube.com/watch?v=2o9AU8MAoq4 "JoeTaxpayer nailed it.  Here's another way to look at it: Generally, we invest in something, then might leave it there for a few years, then take it out, but don't touch it in between.  In that case, to get the final amount X(N), we need to take the initial amount, then multiply by growth in the first year, then multiply by growth in the second year, etc. So, for three years, we have: X(3) = X(0) * G(1) * G(2) * G(3) = X(0) * ""average annual growth"" ^ 3 So, here, we see that we want the average annual growth to the power three equal to the product of the annual growth rates, thus, geometric mean: geometric mean = (G(1) * G(2) * G(3)) ^ (1/3) On the other hand, consider a situation where I have three investments X,Y,Z over one year. Now I have, after one year: X(1)+Y(1)+Z(1) = X(0)*G(1,X) + Y(0)*G(1,Y) + Z(0)*G(1,Z) = ( X(0)+Y(0)+Z(0) ) * ""average annual growth"" Now, in this case, if we assume X(0) = Y(0) = Z(0) = 1, i.e. I put equal amounts in each, we see that the average annual growth rate we want in this case is the arithmetic mean: arithmetic mean = (G(1,X) + G(1,Y) + G(1,Z)) / 3 (if we had unequal amounts at the beginning, it would be a weighted average). 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