Though not exactly a book related to value investing, this oft-cited work of Princeton economist Burton Malkiel discusses many important features of stock market investing. An understanding of its prime contentions is useful for beginners and experts alike.

Malkiel starts the book off by arguing that individual investors can indeed outperform the so-called "experts" on Wall Street by following the principles of the book. The term "random walk" in the title refers to the fact that future steps or directions in the stock market cannot be predicted. Malkiel argues that earnings predictions and chart patterns are useless.

One of the largest threats to investor portfolios is inflation, and while it has been tame in recent decades, Malkiel warns that it may not continue to be so. As the economy continues to become more service-based, Malkiel believes that productivity improvements will be harder to come by, which will drive up prices.

In the rest of the chapter, Malkiel describes and discusses the two approaches used on Wall Street to value assets:

1) The Firm Foundation

Each investment has an intrinsic value. When the price of the investment falls below that value, a buying opportunity exist. Malkiel argues that the logic of this theory is respectable, but that in practice it is very difficult to correctly value a security, because the future is so uncertain.

2) The Castle-In-The-Air

With this method, investors attempt to determine which securities will be popular in the future, and thereby buy before the crowd does. Malkiel also calls this the "Greater Fool" theory, since it suggests that it's allright to pay three times what something is worth as long as later on you can find someone else to pay five times what its worth.

Joel Greenblatt, the book's author, is a value investor extraordinaire and a professor at Columbia's business school. In the book, Greenblatt discusses and justifies the "Magic Formula", a stock selection method that allows individual investors to beat the market using value investing.

For those convinced that the investment strategy encouraged by the book is a good one to follow, Greenblatt offers step by step instructions at the end of the book.

1) Go to magicformulainvesting.com

2) Follow the instructions for company size

3) Follow the instructions for a list of top-ranked magic formula companies

4) Buy 5-7 companies.

5) Repeat steps 1 to 4 every 2-3 months, which should give you 20-30 stocks for the year.

6) Sell each stock after holding for one year

7) Continue for many years. It's important to stick to the strategy, otherwise you may quit before it gets a chance to work.

Greenblatt ends the appendix with a discussion of the efficient market hypothesis, which suggests that the market is priced efficiently. While many studies have shown that various different strategies can beat the market, they have often suffered criticism for overlooking various aspects, such as increased risk, survivorship or look-ahead bias. Greenblatt asserts that the magic formula does not suffer from any of these biases, and works well for both large and small stocks.

A company that makes for a good investment for one value investor does not necessarily make for a good investment for another value investor. How can this be? A company may appear cheap on an earnings or asset basis, but future earnings may not live up to current earnings and assets may be written down. Therefore, only when a company falls within an investor's circle of competence can he ascertain whether a stock is trading at a discount.

Consider ADDvantage Technologies (AEY), a hardware provider for the cable television industry. The company is cheap on many metrics, trading near its net current asset value with a P/B of 0.75 and a P/E of 6. Though sales have fallen dramatically through this downturn, the company has maintained profitability.

Of importance is the company's strategy, however. The company does not manufacture much of the equipment it sells, but is instead a distributor, servicer and value-added reseller to cable companies. One of the major ways in which it adds value for its customers is with its large inventory, allowing for fast delivery of large orders. But the amount of inventory the company carries is far from trivial: it represents 90% of the company's current assets, two-thirds of the company's total assets, and is greater than the company's total equity.

For value investors, the company's strategic decision carry so much inventory has important implications. From one vantage point, the large inventory may represent a margin of safety, as investors are currently afforded the opportunity to purchase this company for less than its inventory. From another point of view, however, the inventory carries a major risk of obsolescence.

Confidence can be placed in the value of inventories of durable goods in slow-changing industries. For example, $30 million worth of screws, nuts and bolts can probably hold their value. But $30 million worth of laptop computers will eventually have to be written down. In which category does the inventory of AEY fall? That depends on the investor's circle of competence.

It is not enough to be able to interpret management's comments on the current value of the company's inventory. Carrying such a large inventory is a major part of the company's strategy going forward, and so cash received from customers will be pumped back into inventory on an ongoing basis. As such, the investor will be constantly subject to the risk of obsolescence. Therefore, only an investor who understands the nature of AEY's products and the speed at which the technology changes can value the company's inventory to some degree of certainty. For everybody else, an investment in this company contains an element of speculation.

Disclosure: None

Though he studied under Ben Graham and has adopted many of Graham's investing principles, the world's greatest investor is not your typical value investor. He speaks of margins of safety and of buying companies at discounts, but over the years Buffett has shown a willingness to buy businesses for what appears to be full price, at least on a P/E basis. What allows Buffett to do this and still generate excellent returns is his ability to understand economic "moats" better than anyone else.

For example, making headlines this week was Buffett's purchase of BNSF (BNI), a railway freight business. While most value investors are using this recession as an opportunity to gobble up companies trading for low P/E and P/B values, Buffett goes out and buys a company for a P/E of 16 (using peak 2008 earnings as the denominator!) and a P/B of 3. Ben Graham himself stated that purchasing companies with P/E ratios above 16 amounts to speculation, so what does Buffett do but make it his largest acquisition to date!

But flirting with high P/E's is nothing new for the Oracle of Omaha, as he has done so on several occasions. What all the high P/E acquisitions have in common, however, is a moat that allows each business to earn superior profits. For example, consider the return on equity (ROE) of BNSF over the last few years:

With the large size of Buffett's portfolio, his investment universe is fairly limited. While most of us have the benefit of being able to turn over every last rock to look for cheap companies, Buffett is limited to selecting from ocean-sized boulders. It is for this reason that BNSF offers an attractive investment opportunity for Buffett. With the ROE depicted above, Buffett will be able to allocate capital to this company (earnings from other businesses, insurance float etc.) and earn returns between 15% and 20%.

If it were this easy though, couldn't all large investors and insurers follow this formula? The advantage Buffett has over everybody else, however, is his superior ability to understand competitive advantages (or "moats"): he believes/knows that the ROE depicted above will continue for the foreseeable future. While he will be second-guessed (always has been, and always will be), his ability to predict moats has proven to be second to none.

Individual investors can certainly learn from Buffett, but are cautioned to avoid investing like him unless they know what they are doing. While Buffett likely benefits from having more information, more knowledge and a higher understanding of business than most investors, his major disadvantage is that his investing universe is so limited. Individuals are thus better off finding value in the analyst-ignored small cap universe where stock prices are the most inefficient and where companies trading at large discounts can be found.

As the market has risen throughout most of this year, many market observers have noted that P/E values are looking rather inflated from a historical standpoint. But of course, earnings are lower than usual this year due to reduced revenue that was caused by financial shocks. So as investors, should we be willing to pay a higher P/E for now, on the assumption that earnings will soon pick up?

When considering the market in the aggregate, this is a very difficult question to answer. Some companies will have cost structures that prove too rigid, and will therefore be unable to adapt to a lower revenue environment. Other companies, on the other hand, will have flexible cost structures or will see revenue continue to grow, despite the downturn. But to determine which of these forces will exert more pull on the market's earnings in the coming quarters is not only extremely difficult, but unnecessary: unless you're trying to value the entire index, you don't have to answer this question for the market in the aggregate. Instead, you can try to answer this question for individual securities, which are much easier to understand.

For example, consider Key Tronic (KTCC), a manufacturer of electronic devices. The company has a P/E of 23, which makes it appear overvalued. But earnings are down because year-over-year quarterly revenue is down 15%. However, the company has little in the way of debt, and has the vast majority of its operating leases coming due in the near-term, giving it further flexibility in reducing its costs. Operating expenses are down 17% this year, and the company sees sales starting to rebound in January of 2010. In fact, based on KTCC's past margins and returns on assets (which it should be able to return to by continuing to cut costs and with a modest recovery in revenues in the years to come), it appears to trade at a normalized P/E much, much lower than the 23 that stock screeners currently display. (KTCC is a stock we've previously discussed here.)

Determining whether the market is over- or under-valued is a difficult exercise indeed. But by focusing only on those companies for which it is easier to compute earnings (circle of competence), and ensuring that companies trade at discounts to those earnings (margin of safety), investors put themselves in positions to profit in the long-term whether the aggregate market offers potential or not.

Disclosure: Author has a long position in shares of KTCC

Contrary to popular belief, increases in aggregate spending (e.g. consumer spending) is not what leads us to a higher standard of living. Nevertheless, both in good times and bad, consumer spending is the gauge the media focuses on as a barometer of how we're doing; but consumer spending is only a measure of short-term demand. Increases in standard of living, however, come from our ability to do our jobs more efficiently.

For example, consider a plant that employs 1000 workers and makes one widget per day. Suppose one day the plant manager comes up with a new method of making that widget, and only requires 500 workers to do it. The remaining workers just got richer, because now the revenue from the widgets sold is spread over fewer workers. (In practice, of course, this process would take time, and the higher profits would be shared among owners and labourers through market forces. Furthermore, the 500 laid off workers would undergo short-term difficulties until they could join a company that's expanding.)

The aggregate nation-wide level of these efficiency improvements is referred to as productivity growth. Here's a look at US productivity growth (in percent) over the last 60 years:

Productivity numbers are reported every quarter, but are not given the attention they deserve. Government policy should be geared towards encouraging productivity gains, which come from savings which leads to investment. Instead, governments often focus on increasing consumer spending, which causes short-term pick-ups in demand (and therefore increases GDP and reduces unemployment in the short-term), but makes us no better off in the long-run.

For companies with high fixed costs, earnings are particularly sensitive to drops in revenue. As a result, we have seen many such companies show negative earnings over the last few quarters. But while reported revenue figures have continued to decline, some backlog numbers have started to tick up, suggesting that for some, higher revenue is on the way. This higher revenue can translate into much higher earnings for companies with fixed costs. For such companies that currently trade at low earnings multiples, strong price appreciation potential exists.

For example, consider Canam (CAM), a company that specializes in designing and building heavy-construction components. Year-over-year quarterly revenue is down over 30%, resulting in a reduction to operating income of over 60%. Despite the revenue shocks, the company has managed to eek out small profits every quarter, and now trades at a P/E multiple under 10 using earnings over the last four quarters.

But these are trough earnings for a company with high fixed costs. Consider the company's backlog over the last several quarters, shown below:

It would appear that revenues will soon be on the mend. Furthermore, subsequent to the end of the Q3 2009 quarter, the company was awarded a $100+ million contract to help build the new roof for BC Place Stadium in Vancouver, which is not included in the above chart.

In addition to the fact that Canam trades at a cheap multiple to trough earnings, Canam has no net debt, and management has recently signaled that it will be buying back and canceling shares. For value investors looking to buy good businesses at attractive prices, Canam may offer such an opportunity.

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Disclosure: Author has a long position in shares of CAM