CHAPTER 13Efficient Markets and Behavioral Finance
Answers to Problem Sets
1. c
2. Weak, semistrong, strong, strong, weak.
3. a. False
b. False
c. True
d. False
e. False
f. True
4. a. False
b. False
c. True
d. False
5. 6 - (-.2 + 1.45 X 5) = -1.05%.
6. a. True
b. False
c. True
d. True
7. Decrease.The stock price already reflects an expected 25% increase. The 20% increaseconveys bad news relative to expectations.
8. a. An investor should not buy or sellshares based on apparent trends or
cycles in returns.
b. A CFO should not speculate on changesin interest rates or foreign
exchange rates. There is no reason to think that the CFO hassuperior information.
c. A financial manager evaluating thecreditworthiness of a large customer
couldcheck the customer’s stock price and the yield on its debt. A fallingstock price or a high yield could indicate trouble ahead.
d. Don’t assume that accounting choicesthat increase or decrease earnings
will have any effect on stock price.
e. The company should not seekdiversification just to reduce risk. Investors
can diversify on their own.
f. Stock issues do not depress price ifinvestors believe the issuer has no private information.
9. a. Evidence that two securities with identical cash flows (e.g.Royal Dutch
Shell and Shell Transport &Trading) can sell at different prices.
b. Small-capstocks and high book-to-market stocks appear to have given above-averagereturns for their level of risk.
c. IPOs provide relatively low returns after their first fewdays of trading.
d. Stocks of firms that announce unexpectedly good earningsperform well
over the coming months.
In each case there appear to havebeen opportunities for earning superior profits.
10. a. Anindividual can do crazy things, butstill not affect the efficiency of markets. The price of the asset in an efficient market is a consensus price aswell as a marginal price. A nutty personcan give assets away for free or offer to pay twice the market value. However, when the person’s supply of assetsor money runs out, the price will adjust back to its prior level (assumingthere is no new, relevant information released by his action). If you are lucky enough to know such aperson, you will receive a positivegain at the nutty investor’s expense. You had better not count on this happening very often, though. Fortunately, an efficient market protectscrazy investors in cases less extreme than the above. Even if
theytrade in the market in an “irrational” manner, they can be assured of getting afair price since the price reflects all information.
b. Yes, and how many people have dropped abundle? Or, more to the point, how manypeople have made a bundle only to lose it later? People can be lucky and some people can bevery lucky; efficient markets do not preclude this possibility.
c. Investor psychology is a slipperyconcept, more often than not used to explain price movements that theindividual invoking it cannot personally explain. Even if it exists, is there any way to makemoney from it? If investor psychologydrives up the price one day, will it do so the next day also? Or will the price drop to a ‘true’level? Almost no one can tell youbeforehand what ‘investor psychology’ will do. Theories based on it have no content.
d. What good is a stable value when youcan’t buy or sell at that value because new conditions or information havedeveloped which make the stable price obsolete? It is the market price, the price at which you can buy or sell today,which determines value.
11. a. There is riskin almost everything you do in daily life. You could lose your job or your spouse, or suffer damage to your housefrom a storm. That doesn’t necessarilymean you should quit your job, get a divorce, or sell your house. If we accept that our world is risky, then wemust accept that asset values fluctuate as new information emerges. Moreover, if capital markets are functioningproperly, then stock price changes will follow a random walk. The random walk of values is the
result of rational investors coping withan uncertain world.
b. To make the example clearer, assumethat everyone believes in the same chart. What happens when the chart shows a downward movement? Are investors going to be willing to hold thestock when it has an expected loss? Ofcourse not. They start selling, and theprice will decline until the stock is expected to give a positive return. The trend will ‘self-destruct.’
c. Random-walk theory as applied toefficient markets means that fluctuations from the
expected outcome are random. Suppose there is an 80 percent chance of rain tomorrow (because it rainedtoday). Then the local umbrella store’sstock price will respond
today to theprospect of high sales tomorrow. Thestore’s
sales will not follow arandom walk, but its stock price will, because each day the stock pricereflects all that investors know about future weather and future sales.
12. One of the ways to think about marketinefficiency is that it implies there is easy money to be made. The following appear to suggest marketinefficiency:
(b) strong form
(d) weak form
(f) semi-strong form
13. The estimates are first substituted inthe market model. Then the result fromthis expected return equation is subtracted from the actual return for themonth to obtain the abnormal return.
Abnormalreturn (Intel) = Actual return –[(−0.57) + (1.08 ′Market return)]
Abnormalreturn (Conagra) = Actual return –[(-0.46) + (0.65 ′Market return)]
14. The efficientmarket hypothesis does not imply that portfolio selection should be done with apin. The manager still has threeimportant jobs to do. First, she mustmake sure that the portfolio is well diversified. It should be noted that a large number ofstocks is not enough to ensure diversification. Second, she must make sure that the risk of the diversified portfolio isappropriate for the manager’s clients. Third, she might want to tailor the portfolio to take advantage ofspecial tax laws for pension funds. These laws may make it possible to increase the expected return of theportfolio without increasing risk.
15. They are bothunder the illusion that markets are predictable and they are wasting their timetrying to guess the market’s direction. Remember the first lesson of market efficiency: Markets have no memory. The decision as to when to issue stock shouldbe made without reference to ‘market cycles.’
16. The efficient-market hypothesis says thatthere is no easy way to make money. Thus, when such an opportunity seems to present itself, we should bevery skeptical. For example:
§
Inthe case of short- versus long-term rates, and borrowing short-term versuslong-term, there are different risks involved. For example, suppose that we need the money long-term but we borrowshort-term. When the short-term note isdue, we must somehow refinance. However;this may not be possible, or may be possible only at a very high interest rate.
§
In the case of Japanese versus United Statesinterest rates, there is the risk that the Japanese yen - U.S. dollar exchangerate will change during the period of time for which we have borrowed.
17. This doespresent some evidence against the efficient capital market hypothesis. One keyto market efficiency is the high level of competition among participants in themarket. For small stocks, the level ofcompetition is relatively low because major market participants (e.g., mutualfunds and pension funds) are biased toward holding the securities of larger,well-known companies. Thus, it isplausible that the market for small stocks is fundamentally different from themarket for larger stocks and, hence, that the small-firm effect is simply areflection of market inefficiency.
But there are at least two alternative possibilities. First, thisdifference might just be coincidental. In statistical inference, we never provean affirmative fact. The best we can dois to accept or reject a specified hypothesis with a given degree ofconfidence. Thus, no matter what theoutcome of a statistical test, there is always a possibility, however slight,that the small-firm effect is simply the result of statistical chance.
Second, firms with small market capitalization may contain some type ofadditional risk that is not measured in the studies. Given the informationavailable and the number of participants, it is hard to believe that anysecurities market in the U.S is not very efficient. Thus, the most likelyexplanation for the small-firm effect is that the model used to estimateexpected returns is incorrect, and that there is some as-yet-unidentified riskfactor.
18. There are several ways to approach thisproblem, but all (when done correctly!) should give approximately the sameanswer. We have chosen to use theregression analysis function of an electronic spreadsheet program to calculatethe alpha and beta for each security. The regressions are in the following form:
Security return = alpha + (beta ′ market return) + error term
The results are:
| Alpha | Beta |
Executive Cheese
| 0.803
| 0.956
|
Paddington Beer
| -0.834
| 0.730
|
Theabnormal return for Executive Cheese in February 2007 was:
–2.1 – [0.803 + 0.956 ′ (–7.7)] = 4.31%
For Paddington Beer, theabnormal return was:
–9.4 – [-0.834+ 0.73 ′ (–7.7)] = –2.95%
Thus, the average abnormal return of the two stocks during the month ofthe earnings announcement was –0.68%.
19. The market ismost likely efficient. The government ofKuwait is not likely to have non-public information about the BP shares. Goldman Sachs is providing an
intermediary service for which they should be remunerated. Stocks are bought by investors at (higher)ask prices and sold at (lower) bid prices. The spread between the two ($0.11) is revenue for the broker. In the U.S., at that time, a bid-ask spreadof 1/8 ($0.125) was not uncommon. The‘profit’ of $15 million reflects the size of the order more than anymispricing.