Editing Discounted cash flow (section)

==Shortcomings==
{{Further|Dividend discount model#Problems with the constant-growth form of the model}}
The following difficulties are identified with the application of DCF in valuation:
# '''Forecast reliability''': Traditional DCF models assume we can accurately forecast revenue and earnings 3–5 years into the future. But studies have shown that growth is neither predictable nor persistent.<ref>{{Cite work|last1=Chan|first1=Louis K.C.|last2=Karceski|first2=Jason|last3=Lakonishok|first3=Josef|date=May 2001|title=The Level and Persistence of Growth Rates|location=Cambridge, MA|doi=10.3386/w8282|doi-access=free}}</ref> (See [[Stock valuation#Growth rate]] and [[Sustainable growth rate#From a financial perspective]].) <br/>In other terms, using DCF models is problematic due to the [[problem of induction]], i.e. presupposing that a sequence of events in the future will occur as it always has in the past. Colloquially, in the world of finance, the problem of induction is often simplified with the common phrase: past returns are not indicative of future results. In fact, the SEC demands that all mutual funds use this sentence to warn their investors.<ref>{{Cite web|url=https://www.sec.gov/fast-answers/answersmperfhtm.html|title=SEC.gov {{!}} Mutual Funds, Past Performance|publisher=U.S. Securities and Exchange Commission|access-date=2019-05-08}}</ref><br/>This observation has led some to conclude that DCF models should only be used to value companies with steady cash flows. For example, DCF models are widely used to value mature companies in stable industry sectors, such as utilities. For industries that are especially unpredictable and thus harder to forecast, DCF models can prove especially challenging. Industry Examples:
#* Real Estate: Investors use DCF models [[Real estate appraisal#The income approach|to value commercial real estate development projects]]. This practice has two main shortcomings. First, the discount rate assumption relies on the market for competing investments at the time of the analysis, which may not persist into the future. Second, assumptions about ten-year income increases are usually based on historic increases in the market rent. Yet the cyclical nature of most real estate markets is not factored in. Most real estate loans are made during boom real estate markets and these markets usually last fewer than ten years. In this case, due to the problem of induction, using a DCF model to value commercial real estate during any but the early years of a boom market can lead to overvaluation.<ref>{{Cite book|last1=Reilly|first1=Robert F.|last2=Schweihs|first2=Robert P.|date=2016-10-28|title=Guide to Intangible Asset Valuation|doi=10.1002/9781119448402|isbn=9781119448402|s2cid=168737069 }}</ref>
#* Early-stage Technology Companies: [[Startup company#Valuations|In valuing startups]], the DCF method can be applied a number of times, with differing assumptions, to assess a range of possible future outcomes—such as the best, worst and mostly likely case scenarios. Even so, the lack of historical company data and uncertainty about factors that can affect the company's development make DCF models especially difficult for valuing startups. There is a lack of credibility regarding future cash flows, future cost of capital, and the company's growth rate. By forecasting limited data into an unpredictable future, the problem of induction is especially pronounced.<ref>{{Citation|chapter=Measuring and Managing Value in High-Tech Start-ups|date=2015-09-12|pages=285–311|publisher=John Wiley & Sons, Inc.|isbn=9781119200154|doi=10.1002/9781119200154.ch18|title=Valuation for M&A}}</ref>
# '''Discount rate estimation''': Traditionally, DCF models assume that the [[capital asset pricing model]] can be used to assess the riskiness of an investment and set an appropriate discount rate. Some economists, however, suggest that the capital asset pricing model has been empirically invalidated.<ref>{{Cite journal|last1=Fama|first1=Eugene F.|last2=French|first2=Kenneth R.|date=2003|title=The Capital Asset Pricing Model: Theory and Evidence|journal=SSRN Working Paper Series|doi=10.2139/ssrn.440920|s2cid=12059689 |issn=1556-5068|url=https://bibliotecadigital.fgv.br/ojs/index.php/rae/article/view/36903 }}</ref> various other models are proposed (see [[asset pricing]]), although all are subject to some theoretical or empirical criticism.
# '''Input-output problem''': DCF is merely a mechanical valuation tool, which makes it subject to the principle "[[garbage in, garbage out]]." Small changes in inputs can result in large changes in the value of a company. This is especially the case with [[Terminal value (finance)|terminal values]], which make up a large proportion of the Discounted Cash Flow's final value.
# '''Missing variables''': Traditional DCF calculations only consider the financial costs and benefits of a decision. They do not include the environmental, social and governance performance of an organization.<ref>{{Cite book|title=Integrated management : how sustainability creates value for any business|last=Sroufe|first=Robert|isbn=978-1787145627|oclc=1059620526|date = 5 October 2018|publisher=Emerald Group }}</ref> This criticism, true for all valuation techniques, is addressed through an approach called "IntFV" discussed below.
<!-- == Example ==
TOO MUCH
To show how discounted cash flow analysis is performed, consider the following example.

: John Doe buys a house for $100,000. Three years later, he expects to be able to sell this house for $150,000.

Simple subtraction suggests that the value of his profit on such a transaction would be $150,000 − $100,000 = $50,000, or 50%. If that $50,000 is [[amortization (business)|amortized]] over the three years, his implied annual return (known as the [[internal rate of return]]) would be about 14.5%. Looking at those figures, he might be justified in thinking that the purchase looked like a good idea. 1.145<sup>3</sup> x $100,000 = $150,000, approximately.

However, since three years have passed between the purchase and the sale, any cash flow from the sale must be discounted accordingly. At the time John Doe buys the house, the three-year [[United States Treasury security#Treasury note|US Treasury Note]] rate is 5% per annum. Treasury notes are generally considered to be inherently less risky than real estate, since the value of the note is guaranteed by the US government and there is a [[liquidity|liquid]] market for the purchase and sale of T-notes. If he had not put his money into buying the house, he could have invested it in the relatively safe T-Notes instead. This 5% per annum can, therefore, be regarded as the [[risk-free interest rate]] for the relevant period (three years).

Using the DPV formula above (FV=$150,000, i=0.05, n=3), that means that the value of $150,000 received in three years actually has a [[present value]] of $129,576 (rounded off). In other words, we would need to invest $129,576 in a T-bond now to get $150,000 in three years almost risk-free. This is a quantitative way of showing that money in the future is not as valuable as money in the present ($150,000 in three years is not worth the same as $150,000 now; it is worth $129,576 now).
Subtracting the purchase price of the house ($100,000) from the [[present value]] results in the [[net present value]] of the whole transaction, which would be $29,576 or a little more than 29% of the purchase price. Another way of looking at the deal as the excess return achieved (over the risk-free rate) is (114.5 - 105)/(100 + 5) or approximately 9.0% (still very respectable).

But what about risk? We assume that the $150,000 is John's best estimate of the sale price that he will be able to achieve in three years time (after deducting all expenses). There is a lot of uncertainty about house prices, and the outcome may end up higher or lower than this estimate. (The house John is buying is in a "good neighborhood", but market values have been rising quite a lot lately and the real estate market analysts in the media are talking about a slow-down and higher interest rates. There is a probability that John might not be able to get the full $150,000 he is expecting in three years due to a slowing of price appreciation, or that loss of liquidity in the real estate market might make it very hard for him to sell at all.

Under normal circumstances, people entering into such transactions are [[risk-averse]], that is to say that they are prepared to accept a lower expected return for the sake of avoiding risk. See [[Capital asset pricing model]] for a further discussion of this. For the sake of the example (and this is a gross simplification), let us assume that he values this particular risk at 5% per annum (we could perform a more precise probabilistic analysis of the risk, but that is beyond the scope of this article). Therefore, allowing for this risk, his expected return is now 9.0% per annum (the arithmetic is the same as above). And the excess return over the risk-free rate is now (109 - 105)/(100 + 5) which comes to approximately 3.8% per annum.

That return rate may seem low, but it is still positive after all of our discounting, suggesting that the investment decision is probably a good one: it produces enough profit to compensate for tying up capital and incurring risk with a little extra left over. When investors and managers perform DCF analysis, the important thing is that the net present value of the decision after discounting all future cash flows at least be positive (more than zero). If it is negative, that means that the investment decision would actually ''lose'' money even if it appears to generate a nominal profit. For instance, if the expected sale price of John Doe's house in the example above was not $150,000 in three years, but ''$130,000'' in three years or $150,000 in ''five'' years, then on the above assumptions buying the house would actually cause John to ''lose'' money in present-value terms (about $3,000 in the first case, and about $8,000 in the second). Similarly, if the house was located in an undesirable neighborhood and the [[Federal Reserve Bank]] was about to raise interest rates by five percentage points, then the risk factor would be a lot higher than 5%: it might not be possible for him to predict a profit in discounted terms even if he thinks he could sell the house for ''$200,000'' in three years.

In this example, only one future cash flow was considered.  For a decision which generates multiple cash flows in multiple time periods, all the cash flows must be discounted and then summed into a single [[net present value]]. See [[#Methods of appraisal of a company or project]] for cases where multiple periods are considered. -->