Jonathan Lewellen

Learning, Asset-Pricing Tests, and Market Efficiency

This paper studies the asset-pricing implications of parameter uncertainty. We show that, when investors must learn about expected cash flows, empirical tests can find patterns in the data that differ from those perceived by rational investors. Returns might appear predictable to an econometrician, or appear to deviate from the Capital Asset Pricing Model, but investors can neither perceive nor exploit this predictability. Returns may also appear excessively volatile even though prices react efficiently to cash-flow news. We conclude that parameter uncertainty can be important for characterizing and testing market efficiency.

Stock Returns, Aggregate Earnings Surprises, and Behavioral Finance

We study the stock market reaction to aggregate earnings news. Previous research shows that, for individual firms, stock prices react positively to earnings news but require several quarters to fully reflect the information in earnings. We find that the relation between returns and earnings is substantially different in aggregate data. First, returns are unrelated to past earnings, suggesting that prices neither underreact nor overreact to aggregate earnings news. Second, aggregate returns are negatively correlated with concurrent earnings; over the last 30 years, stock prices increased 6.5% in quarters with negative earnings growth and only 1.9% otherwise. This finding suggests that earnings and discount rates move together over time, and provides new evidence that discount-rate shocks explain a significant fraction of aggregate stock returns.

The Cross-section of Expected Stock Returns

This paper studies the cross-sectional properties of return forecasts derived from Fama-MacBeth regressions. These forecasts mimic how an investor could, in real time, combine many firm characteristics to obtain a composite estimate of a stock’s expected return. Empirically, the forecasts vary substantially across stocks and have strong predictive power for actual returns. For example, using ten-year rolling estimates of Fama- MacBeth slopes and a cross-sectional model with 15 firm characteristics (all based on low-frequency data), the expected-return estimates have a cross-sectional standard deviation of 0.87% monthly and a predictive slope for future monthly returns of 0.74, with a standard error of 0.07.

Investment and Cash Flow: New Evidence

We provide new estimates of investment-cashflow sensitivities for a large cross section of U.S. firms from 1971–2006. Our tests extend the literature in several key ways and provide strong evidence that cashflow matters beyond its correlation with a firm’s investment opportunities. Controlling only for M/B, a dollar of currentand prior-year cashflow is associated with

The Behavior of Aggregate Corporate Investment

0.59 of additional investment for firms that are the least likely to be constrained and

The Predictive Power of Investment and Accruals

0.75 for firms that are the most likely to be constrained. Investment-cashflow sensitivities for the two groups drop to a conservatively estimated but still significant 0.32 and 0.67, respectively, after correcting for measurement error in M/B (our proxy for Q). The results suggest that financing constraints and, perhaps, free cashflow problems are important for investment decisions.

A Skeptical Appraisal of Asset Pricing Tests

We study the behavior of aggregate corporate investment from 1952-2010. Investment grows rapidly following high profits and stock returns but, contrary to standard predictions, is largely unrelated to recent changes in market volatility, interest rates, or the default spread on corporate bonds. At the same time, high investment predicts negative profit growth going forward and is associated with low stock returns when investment data are publicly released, suggesting that a jump in investment coincides with bad news. Our analysis also shows that the investment decline following the financial crisis of 2008 was not unusual given the drop in GDP and profits at the end of 2008.

Predicting Returns with Financial Ratios

We test whether investment explains the accrual anomaly by splitting total accruals into investment-related and “nontransaction” accruals, items such as depreciation and asset write-downs that do not represent new investment expenditures. The two types of accruals have very different predictive power for firm performance, not just for future earnings but also for future cash flow and stock returns. Most importantly, nontransaction accruals have the strongest negative predictive slopes for earnings and stock returns, contrary to the predictions of the investment hypothesis. A long-short portfolio based on nontransaction accruals has a significant average return of 0.71 % monthly from 1972 to 2010 and remains profitable at the end of the sample when returns on other accrual strategies decline. Our results suggest that nontransaction accruals are the least reliable component of accruals and show that a significant portion of the accrual anomaly cannot be explained by investment.