One of the most fascinating examples of the phenomenon of mean reversion was identified by Werner F.M. DeBondt and Richard H. Thaler in Further Evidence on Investor Overreaction and Stock Market Seasonality. DeBondt and Thaler examined the relative performance of quintiles of stocks on the NYSE and AMEX ranked according to book value. As an adjunct to the main study, one of the variables they analyzed was the relative earnings performance of stocks in the lowest and highest price-to-book quintiles.
DeBondt and Thaler’s findings are as interesting as they are counter-intuitive. Stocks in the lowest price-to-book quintile (the cheapest stocks) grew their earnings faster than the stocks in the highest price-to-book quintile (the most expensive stocks). Tweedy Browne set out DeBondt and Thaler’s findings in Table 3 below, which describes the average earnings per share for companies in the lowest and highest quintile of price-to-book value in the three years prior to selection and the four years subsequent to selection:
In the four years after the date of selection, the earnings of the companies in the lowest price-to-book value quintile (average price-to-book value of 0.36) increase 24.4%, more than the companies in the highest price-to-book value quintile (average price-to-book value of 3.42), whose earnings increased only 8.2%. DeBondt and Thaler attribute the earnings outperformance of the companies in the lowest quintile to mean reversion, which Tweedy Browne described as the observation that “significant declines in earnings are followed by significant earnings increases, and that significant earnings increases are followed by slower rates of increase or declines.”
The implication here is that not only does the price of stocks that are cheap relative to other stocks regress to the mean, but the underlying performance does too. That’s an amazing finding. There’s really no good reason why low price-to-book should be such a good predictor for short and mid-term earnings growth. I’ve spent some time thinking about why this might be so, and the only possible explanation I can come up with is magic. Nothing else fits.
Greenbackd
http://greenbackd.com
DeBondt and Thaler’s findings are as interesting as they are counter-intuitive. Stocks in the lowest price-to-book quintile (the cheapest stocks) grew their earnings faster than the stocks in the highest price-to-book quintile (the most expensive stocks). Tweedy Browne set out DeBondt and Thaler’s findings in Table 3 below, which describes the average earnings per share for companies in the lowest and highest quintile of price-to-book value in the three years prior to selection and the four years subsequent to selection:
In the four years after the date of selection, the earnings of the companies in the lowest price-to-book value quintile (average price-to-book value of 0.36) increase 24.4%, more than the companies in the highest price-to-book value quintile (average price-to-book value of 3.42), whose earnings increased only 8.2%. DeBondt and Thaler attribute the earnings outperformance of the companies in the lowest quintile to mean reversion, which Tweedy Browne described as the observation that “significant declines in earnings are followed by significant earnings increases, and that significant earnings increases are followed by slower rates of increase or declines.”
The implication here is that not only does the price of stocks that are cheap relative to other stocks regress to the mean, but the underlying performance does too. That’s an amazing finding. There’s really no good reason why low price-to-book should be such a good predictor for short and mid-term earnings growth. I’ve spent some time thinking about why this might be so, and the only possible explanation I can come up with is magic. Nothing else fits.
Greenbackd
http://greenbackd.com
