Understanding volatility is crucial for informed investment decisions. Our paper explores the volatility of the market, size, and value premiums of the Fama-French three-factor model for US equity returns.

Volatility and Premiums in US Equity Returns (PDF)

EFF/KRF: We are not experts, but know enough about the academic research to be skeptical of the signals suggested by casual observers. The academics who study this find that the best leading indicators are not very powerful. It is hard to say when the recession will end until it has.

From an investment perspective, the market is always doing its best to incorporate information about future business conditions in current prices. As a result, other signals about the end of the recession are not likely to help you forecast the market.

EFF/KRF: In our research we calculate the E/P ratio for a portfolio just as S&P does, dividing the aggregate earnings of the firms in the portfolio by the total market equity. It is easy to see the logic if you imagine merging all of the firms into one giant conglomerate. The new firm's earnings and market equity are just the sum of the individual firms' earnings and market equity.

EFF: It gives investors a good estimate of what a financial institution is worth. It has more flexibility than commonly realized, especially for illiquid assets, where best estimates of value can be used.

KRF: There is not enough empirical evidence to be sure who is right about this issue, but we can guess. Those against marking to market argue that the transaction prices for securities sold under duress do not reflect their true value. If you and I both own relatively illiquid assets and you choose to sell yours quickly at a fire sale price, mark to market accounting may force me to write down the value of my assets to your transaction price. Unless I also plan to sell my position quickly, this undervalues my position. The critical question, however, is whether your transaction price is more accurate than the model value I would use if I am not forced to mark to market. My guess—and this is only a guess—is that the observed transaction price is typically more accurate than the model. In other words, marking to market would improve the accuracy of my balance sheet.

EFF/KRF: In the past, other countries have had recessions that the U.S. has not shared. But the U.S. is big, and every U.S. recession has been global. Thus, the global aspect of the current U.S. recession is characteristic of past U.S. recessions. Every past recession has ended. This one will too.

EFF/KRF: The recent sharp decline in prices suggests that the market does not think the actions of the government (including the stimulus plan) are, in aggregate, good for the economy. If you think the market has it right, then expected stock returns are high, for the reasons outlined above. If you are more pessimistic than the market about the effects of government actions, then (at least on this score) you think prices are too high, which means expected returns are low. Conversely, if you are more optimistic than the market about the effects of government actions, then you think prices are too low, which means expected returns are quite high. Keep in mind, however, that the empirical evidence says you are on thin ice when you decide your forecast of the future is better than the market's.

EFF/KRF: The market has declined sharply in response to rough times and forecasts of future rough times. The decline in market prices combines two effects: (i) lower current and expected future profits, and (ii) higher discount rates for the expected future profits. The discount rate, in turn, has increased because uncertainty about future profits (in other words, risk) has increased and, apparently, because investors have become more risk averse. Higher discount rates for expected profits translate into higher expected stock returns.

EFF: This is a market timing question, and there is no evidence that anyone can predict markets or the duration of market episodes. Unfortunately, the same is true for business cycles. The average length of contractions during the post WW II period is about a year. But since there are so few observations on contractions, this historical evidence is not much of a guide.

KRF: This question has several interpretations. Perhaps the simplest is, "How long will prices continue to fall?" Since we are never certain what stock prices will do next, we cannot be sure they have stopped falling, but there is no reason to expect the market to go down over the next year, month, or even day. In fact, the historical evidence suggests that, rather than being negative, expected stock returns are unusually high in recessions to compensate investors for the additional risk they bear during these turbulent periods.

The question can also be interpreted as, "Gosh, we've lost a lot of money in the market. When will we get it back?" There is bad news and slightly better news here. First the bad news. Much of the drop in prices is permanent and reflects the reduction in profits firms have suffered and will continue to suffer as a result of the recession. This reduction is real and will have a permanent impact on firm values and security prices.

The good news -- if you want to call it that -- is that part of the price drop is probably temporary. Just as bond prices must fall when interest rates go up, if some combination of greater uncertainty about economic conditions and an increase in aggregate risk aversion increases expected stock returns, stock prices must fall to accommodate the higher expected returns. And this part of the losses is temporary; we expect to recover the price drop through higher future returns. Of course, the increase in expected returns we are talking about is not free. Any increase in expected stock returns is likely attributable to an increase in market risk and possibly an increase in risk aversion.

EFF: The evidence that short-sellers actually know something about market prices is weak. And even if they do, they only push prices more quickly to lower equilibrium levels, so they have little effect on the returns of long-term investors.

EFF/KRF: When market volatility goes up, cross-country and cross-asset-class correlations tend to go up. When market volatility is normal, events that are specific to countries, asset classes, or individual firms are a larger part of total volatility and correlations are low. When market volatility increases relative to other sources of volatility, the common variation becomes a larger part of total volatility and correlations go up. This effect has been particularly apparent recently because volatility has been extraordinarily high.

EFF/KRF: Stock prices would go down and T-bill prices would go up - the usual response of prices to changes in demand. Of course, when T-bill prices go up the yield falls. Similarly, a reduction in prices caused by a large number of investors moving out of stocks pushes expected returns up.