Knowledge that Transforms

In this article, I explicitly solve dynamic portfolio choice problems, up to the solution of an ordinary differential equation (ODE), when the asset returns are quadratic and the agent has a constant relative risk aversion (CRRA) coefficient. My solution includes as special cases many existing explicit solutions of dynamic portfolio choice problems. I also present three applications that are not in the literature. Application 1 is the bond portfolio selection problem when bond returns are described by “quadratic term structure models.” Application 2 is the stock portfolio selection problem when stock return volatility is stochastic as in Heston model. Application 3 is a bond and stock portfolio selection problem when the interest rate is stochastic and stock returns display stochastic volatility.

We develop a model for an investor with multiple priors and aversion to ambiguity. We characterize the multiple priors by a "confidence interval" around the estimated expected returns and we model ambiguity aversion via a minimization over the priors. Our model has several attractive features: (1) it has a solid axiomatic foundation; (2) it is flexible enough to allow for different degrees of uncertainty about expected returns for various subsets of assets and also about the return-generating model; and (3) it delivers closed-form expressions for the optimal portfolio. Our empirical analysis suggests that, compared with portfolios from classical and Bayesian models, ambiguity-averse portfolios are more stable over time and deliver a higher out-of sample Sharpe ratio.

This article uses managerial control rights data for over 5000 firms from 31 countries to examine the net costs and benefits of cash holdings. We find that when external country-level shareholder protection is weak, firm values are lower when controlling managers hold more cash. Further, when external shareholder protection is weak we find that firm values are higher when controlling managers pay dividends. Only when external shareholder protection is strong do we find that cash held by controlling managers is unrelated to firm value, consistent with generally prevailing U.S. and international evidence.

We develop a one-period model of investor asset holdings where investors have heterogeneous preference for skewness. Introducing heterogeneous preference for skewness allows the model's investors, in equilibrium, to underdiversify. We find support for our model's three key implications using a dataset of 60,000 individual investor accounts. First, we document that the portfolio returns of underdiversified investors are substantially more positively skewed than those of diversified investors. Second, we show that the apparent mean-variance inefficiency of underdiversified investors can be largely explained by the fact that investors sacrifice mean-variance efficiency for higher skewness exposure. Furthermore, we show that idiosyncratic skewness, and not just coskewness, can impact equilibrium prices. Third, the underdiversification of investors does not appear to be coincidentally related to skewness. Stocks most often selected by underdiversified investors have substantially higher average skewness—especially idiosyncratic skewness—than stocks most often selected by diversified investors.

This article examines how in a context of limited enforceability of contracts suppliers may have a comparative advantage over banks in lending to customers because they are able to stop the supply of intermediate goods. Suppliers may act also as liquidity providers, insuring against liquidity shocks that could endanger the survival of their customer relationships. The relatively high implicit interest rates of trade credit are the result of insurance and default premiums that are amplified whenever suppliers face a relatively high cost of funds. I explore these effects empirically for a panel of UK firms.

Given the cross-sectional and temporal variation in their liquidity, emerging equity markets provide an ideal setting to examine the impact of liquidity on expected returns. Our main liquidity measure is a transformation of the proportion of zero daily firm returns, averaged over the month. We find that it significantly predicts future returns, whereas alternative measures such as turnover do not. Consistent with liquidity being a priced factor, unexpected liquidity shocks are positively correlated with contemporaneous return shocks and negatively correlated with shocks to the dividend yield. We consider a simple asset-pricing model with liquidity and the market portfolio as risk factors and transaction costs that are proportional to liquidity. The model differentiates between integrated and segmented countries and time periods. Our results suggest that local market liquidity is an important driver of expected returns in emerging markets, and that the liberalization process has not fully eliminated its impact.

We examine the predictive power of the dividend yields for forecasting excess returns, cash flows, and interest rates. Dividend yields predict excess returns only at short horizons together with the short rate and do not have any long-horizon predictive power. At short horizons, the short rate strongly negatively predicts returns. These results are robust in international data and are not due to lack of power. A present value model that matches the data shows that discount rate and short rate movements play a large role in explaining the variation in dividend yields. Finally, we find that earnings yields significantly predict future cash flows.

The article shows that two measures of the amount of private information in stock price—price nonsynchronicity and probability of informed trading (PIN)—have a strong positive effect on the sensitivity of corporate investment to stock price. Moreover, the effect is robust to the inclusion of controls for managerial information and for other information-related variables. The results suggest that firm managers learn from the private information in stock price about their own firms’ fundamentals and incorporate this information in the corporate investment decisions. We relate our findings to an alternative explanation for the investment-to-price sensitivity, namely that it is generated by capital constraints, and show that both the learning channel and the alternative channel contribute to this sensitivity.

Pledgeable assets support more borrowing, which allows for further investment in pledgeable assets. We use this credit multiplier to identify the impact of financing frictions on corporate investment. The multiplier suggests that investment–cash flow sensitivities should be increasing in the tangibility of firms' assets (a proxy for pledgeability), but only if firms are financially constrained. Our empirical results confirm this theoretical prediction. Our approach is not subject to the Kaplan and Zingales (1997) critique, and sidesteps problems stemming from unobservable variation in investment opportunities. Thus, our results strongly suggest that financing frictions affect investment decisions.

[In 2001, the Securities and Exchange Commission (SEC) required market centers to publish monthly execution-quality reports in an effort to spur competition for order flow between markets. Using samples of stocks trading on several markets, we investigate whether past execution quality affects order-routing decisions and whether the new disclosure requirements influence this relationship. We find that routing decisions are associated with execution quality; markets reporting low execution costs and fast fills subsequently receive more orders. Moreover, the reports themselves appear to provide information that was 2unavailable previously. Our results are consistent with active competition for order flow that can be influenced by public disclosure.]