Comment on "The Spirit of Capitalism and Stock Market Prices" By G.S. Bakshi and Z. Chen (AER, 1996)

share prices;capitalism;financial markets

Why is Long-Horizon Equity Less Risky? A Duration-Based Explanation of the Value Premium

This paper proposes a dynamic risk-based model that captures the high expected returns on value stocks relative to growth stocks, and the failure of the capital asset pricing model to explain these expected returns. To model the difference between value and growth stocks, we introduce a cross-section of long-lived firms distinguished by the timing of their cash flows. Firms with cash flows weighted more to the future have high price ratios, while firms with cash flows weighted more to the present have low price ratios. We model how investors perceive the risks of these cash flows by specifying a stochastic discount factor for the economy. The stochastic discount factor implies that shocks to aggregate dividends are priced, but that shocks to the time-varying price of risk are not. As long-horizon equity, growth stocks covary more with this time-varying price of risk than value stocks, which covary more with shocks to cash flows. When the model is calibrated to explain aggregate stock market behavior, we find that it can also account for the observed value premium, the high Sharpe ratios on value stocks relative to growth stocks, and the outperformance of value (and underperformance of growth) relative to the CAPM.

Can Habit Formation be Reconciled with Business Cycle Facts?

Many asset pricing puzzles can be explained when habit formation is added to standard preferences. We show that utility functions with a habit then gives rise to a puzzle of consumption volatility in place of the asset pricing puzzles when agents can choose consumption and labor optimally in response to more fundamental shocks. We show that the consumption reaction to technology shocks are too small by an order of magnitude when a utility includes a habit. Alternative models with consistent and exogenous but stochastic labor input are considered. A model with persistent technology shocks and stochastic labor is shown to be potentially consistent with substantial consumption variability aswell as procyclical labor input and labor productivity even when a habit is present.

Rule of Thumb and Dynamic Programming

This paper studies the relationships between learning about rules of thumb (represented by classifier systems) and dynamic programming. Building on a result about Markovian stochastic approximation algorithms, we characterize all decision functions that can be asymptotically obtained through classifier system learning, provided the asymptotic ordering of the classifiers is strict. We demonstrate in a robust example that the learnable decision function is in general not unique, not characterized by a strict ordering of the classifiers, and may not coincide with the decision function delivered by the solution to the dynamic programming problem even if that function is attainable. As an illustration we consider the puzzle of excess sensitivity of consumption to transitory income: classifier systems can generate such behavior even if one of the available rules of thumb is the decision function solving the dynamic programming problem, since bad decisions in good times can "feel better" than good decisions in bad times.

Understanding Trend and Cycle in Asset Values: Reevaluating the Wealth Effect on Consumption

Both textbook economics and common sense teach us that the value of household wealth should be related to consumer spending. At the same time, movements in asset values often seem disassociated with important movements in consumer spending, as episodes such as the 1987 stock market crash and the contraction in equity values that occurred in the fall of 1998 suggest. An important first step in understanding the consumption-wealth linkage is determining how closely the two variables are actually correlated, and whether there exist important movements in asset values that are not associated with changes in consumption. This paper provides evidence that a surprisingly small fraction of the variation in household net worth is related to variation in aggregate consumer spending. We use empirical techniques that allow us to quantify the relative importance of permanent and transitory innovations in the variation of consumer spending and wealth and find that transitory shocks dominate post-war variation in wealth, while permanent shocks dominate variation in aggregate consumption. Although transitory innovations are found to have little influence on consumer spending, they have long-lasting effects on wealth , exhibiting a half-life of a little over two years. The findings suggest that most macro models which make no allowance for transitory variation in wealth that is orthogonal to consumption are likely to misstate both the timing and magnitude of the consumption-wealth linkage.

Expected Returns and Expected Dividend Growth

We investigate a consumption-based present value relation that is a function of future dividend growth. Using data on aggregate consumption and measures of the dividend payments from aggregate wealth, we show that changing forecasts of dividend growth make an important contribution to fluctuations in the U.S. stock market, despite the failure of the dividend-price ratio to uncover such variation. In addition, these dividend forecasts are found to covary with changing forecasts of excess stock returns. The variation in expected dividend growth we uncover is positively correlated with changing forecasts of excess returns and occurs at business cycle frequencies, those ranging from one to six years. Because positively correlated fluctuations in expected dividend growth and expected returns have offsetting affects on the log dividend-price ratio, the results imply that both the market risk-premium and expected dividend growth vary considerably more than what can be revealed using the log dividend-price ratio alone as a predictive variable.

How Elastic is the Firm's Demand for Health Insurance?

We investigate the impact of tax subsidies on the firms decision to offer insurance, and on conditional firm spending on insurance. We do so using the micro-data underlying the Employee Compensation Index, which has a major advantage for this exercise: the matching of very high quality compensation data with information on a sample of workers in the firm. We find that, overall, there is a modest elasticity of insurance offering with respect to after-tax prices (elasticity of -0.31 to -0.41), but a larger elasticity of insurance spending (elasticity of 0.66 to 0.99). We also find that the elasticity of offering is driven solely by small firms, for whom the elasticity is much larger, but that spending is more elastic in large firms. We provide some evidence on how the aggregation of worker preferences determines benefits provision decisions. In particular, we find evidence to support a median voter model of benefits determination, along with some additional influence for the most highly compensated workers in the firm. Our simulation results suggest that major tax reform could lead to an enormous reduction in employer-provided health insurance spending.

Robustness of adaptive expectations as an equilibrium selection device

Equilibrium Theory;Rational Expectations