Rating transition matrices for sovereigns are an important input to risk management of portfolios of emerging market credit exposures. They are widely used both in credit portfolio management and to calculate future loss distributions for pricing purposes. However, few sovereigns and almost no low credit quality sovereigns have ratings histories longer than a decade, so estimating such matrices is difficult. This paper shows how one may combine information from sovereign defaults observed over a longer period and a broader set of countries to derive estimates of sovereign transition matrices.

This paper examines data from 45 world markets and shows that the previously documented relation between mean returns and idiosyncratic volatility arises because of biases in volatility estimates that we can attribute to the bid–ask bounce in trade prices. We show that no significant relation exists between mean returns and idiosyncratic volatility estimated from quote-midpoint returns. Further, there is no significant relation between mean returns and the portion of transaction-price-based idiosyncratic volatility that is orthogonal to bid–ask spreads. The pricing of idiosyncratic volatility is due to the negative pricing of the bid–ask spread.

We provide evidence that a simple moving average timing strategy, when applied to portfolios of commodity futures, can generate superior performance to the buy-and-hold strategy. The outperformance is very robust. It can survive the transaction costs in the futures markets, it is not concentrated in a particular subperiod, and is robust to short-sale constraints, alternative specifications of the moving average lag length, alternative construction of the continuous time-series of futures prices, and impact from data mining. The outperformance of the timing strategy is not driven by the backwardation and contango. It is stronger during recession and can not be explained by macroeconomic variables. Finally, we confirm that the outperformance of the moving average timing strategy in the commodity futures comes from the successful market timing.