[This paper investigates the international asset allocation effects of time-variations in higherorder moments of stock returns such as skewness and kurtosis. In the context of a fourmoment International Capital Asset Pricing Model (ICAPM) specification that relates stock returns in five regions to returns on a global market portfolio and allows for time-varying prices of covariance, co-skewness, and co-kurtosis risk, we find evidence of distinct bull and bear regimes. Ignoring such regimes, an unhedged US investor's optimal portfolio is strongly diversified internationally. The presence of regimes in the return distribution leads to a substantial increase in the investor's optimal holdings of US stocks, as does the introduction of skewness and kurtosis preferences.]

This paper extends the literature on analyst optimism. Our analysis of a large sample of recommendations issued from 1995 through 2006 indicates that sell-side analysts are likely to assign frequent and favorable ratings to a stock after the analysts’ affiliated mutual funds invest in that stock. Controlling for a number of variables, including the ties between analysts and investment banks, we find that the greater the portfolio weight of a stock in the fund family, the more optimistic the stock ratings from affiliated analysts become. Since 2002, analysts’ optimism on stocks held by affiliated mutual funds has declined. However, an analyst's decision of upgrading a stock to a “strong buy” rating is still significantly associated with the portfolio weight of that stock in the fund family.

This paper studies the relationship between civil war and the value of firms in a poor, resource-abundant country using microeconomic data for Angola. We focus on diamond mining firms and conduct an event study on the sudden end of the conflict, marked by the death of the rebel movement leader in 2002. We find that the stock market perceived this event as “bad news” rather than “good news” for companies holding concessions in Angola, as their abnormal returns declined by 4 percentage points. The event had no effect on a control portfolio of otherwise similar diamond mining companies. This finding is corroborated by other events and by the adoption of alternative methodologies. We interpret our findings in light of conflict-generated entry barriers, government bargaining power, and transparency in the licensing process. (JEL D74, G32, O13, O17, Q34)

We examine asset allocation decisions under smooth ambiguity aversion when an investor has a prior degree of belief in an asset pricing model (e.g., the domestic CAPM). Different from a Bayesian approach, the investor separately relies on the conditional distribution of returns and on the posterior over parameters to make decisions, rather than on the predictive distribution of returns that integrates priors and likelihood information. We find that in the perspective of US investors, ambiguity aversion generates strong home bias in equity holdings, regardless of beliefs in the CAPM or risk aversion. Results become stronger under regime-switching investment opportunities.

This paper investigates the international asset allocation effects of time-variations in higher-order moments of stock returns such as skewness and kurtosis. In the context of a four-moment International Capital Asset Pricing Model (ICAPM) specification that relates stock returns in five regions to returns on a global market portfolio and allows for time-varying prices of covariance, co-skewness, and co-kurtosis risk, we find evidence of distinct bull and bear regimes. Ignoring such regimes, an unhedged US investor's optimal portfolio is strongly diversified internationally. The presence of regimes in the return distribution leads to a substantial increase in the investor's optimal holdings of US stocks, as does the introduction of skewness and kurtosis preferences.

We examine whether the dynamics of the implied volatility surface of individual equity options contains exploitable predictability patterns. Predictability in implied volatilities is expected due to the learning behavior of agents in option markets. In particular, we explore the possibility that the dynamics of the implied volatility surface of individual stocks may be associated with movements in the volatility surface of S&P 500 index options. We present evidence of strong predictable features in the cross-section of equity options and of dynamic linkages between the volatility surfaces of equity and S&P 500 index options. Moreover, time-variation in stock option volatility surfaces is best predicted by incorporating information from the dynamics in the surface of S&P 500 options. We analyze the economic value of such dynamic patterns using strategies that trade straddle and delta-hedged portfolios, and find that before transaction costs such strategies produce abnormal risk-adjusted returns.

It is often suggested that through a judicious choice of predictors that track business cycles and market sentiment, simple vector autoregressive (VAR) models could produce optimal strategic portfolio allocations that hedge against the bull and bear dynamics typical of financial markets. However, a distinct literature exists that shows that nonlinear econometric frameworks, such as Markov switching (MS), are also natural tools to compute optimal portfolios in the presence of stochastic good and bad market states. In this paper we examine whether simple VARs can produce portfolio rules similar to those obtained under MS, by studying the effects of expanding both the order of the VAR and the number/selection of predictor variables included. In a typical stock–bond strategic asset allocation problem, we compute the out-of-sample certainty equivalent returns for a wide range of VARs and compare these measures of performance with those typical of nonlinear models for a long-horizon investor with constant relative risk aversion. We conclude that most VARs cannot produce portfolio rules, hedging demands, or (net of transaction costs) out-of-sample performances that approximate those obtained from equally simple nonlinear frameworks. We also compute the improvement in realized performance that may be achieved adopting more complex MS models and report this may be substantial in the case of regime switching ARCH.

We investigate the lead-lag relationships between issuer-paid and investor-paid credit rating agencies (CRAs), after the regulatory reforms in the U.S. (2002–2006) also including outlooks. Over our sample period, ratings (but not outlooks) issued by issuer-paid agencies were certified by the SEC while investor-paid agencies were not certified at all. First, in the wake of the reforms, we find a weaker lead effect of investor-paid over issuer-paid CRAs: after 2002, causality turned bi-directional. Second, after the overhaul of the rating business, issuer-paid CRAs behave less conservatively when dealing with outlook changes than with rating changes, which is consistent with a more conservative approach to ratings than to outlooks, because of the effects of the SEC's certification. Third, investor-paid downgrades become associated with more negative, statistically significant abnormal stock returns, than issuer-paid downgrades are. These results support the hypothesis that issuer-paid CRAs improved the timeliness of their ratings because of the recently implemented, tighter regulations. However, differences in abnormal returns imply that investor-paid rating actions still carry superior information. Adding data from the post NRSRO status acquisition by Egan Jones Ratings, the investor-paid agency studied in our paper, does not radically affect our results and confirms that some of the previously observed differences in timeliness and market impact have been fading over time.

We study the effects of a conventional monetary expansion, quantitative easing, and the maturity extension program on corporate bond yields using impulse response functions obtained from flexible models with regimes. Using a three-state Markov switching model with time-homogeneous vector autoregressive (VAR) coefficients that emerges from a systematic model specification search, we find that unconventional policies may have been generally expected to decrease both corporate yields and spreads. However, even though the sign of the responses is the one desired by policymakers, the size of the estimated effects depends on the assumptions regarding the decline in long-term Treasury yields caused by unconventional policies, on which considerable uncertainty remains. Further tests based on yield spreads and a variable that measures inflation expectations show that, in the crisis regime, unconventional monetary policies do not produce any perverse effects on expected inflation. These results prove robust to adopting a framework that allows VAR coefficients to break, to imposing coefficient restrictions that increase parsimony, and to a range of different ordering schemes that identify shocks in alternative ways.