Should long-term investors account for time-variation in model parameters? We develop a time-varying Vector Autoregressive model that can handle time-variation in intercepts, slopes, volatility and correlation, the leverage effect in volatility and fat tails. Long-term investors should take...

We study the effect of parameter uncertainty on the long-run risk of three alternative asset classes: equity, nominal bonds and short-term T-Bills. We estimate the long-run risk as the annualized predictive variance of returns at different horizons implied by a vector autoregression using...

These working notes on algorithmic trading are designed as an introduction to the basic equations that govern the day-to-day trading of an investment portfolio to meet a predefined strategic asset allocation. The algebraic framework applies generally to long only and long/short strategies. It...

This paper examines how the size of the rolling window, and the frequency used in moving average (MA) trading strategies, affects financial performance when risk is measured. We use the MA rule for market timing, that is, for when to buy stocks and when to shift to the risk-free rate. The...

We study empirical mean-variance optimization when the portfolio weights are restricted to be direct functions of underlying stock characteristics such as value and momentum. The closed-form solution to the portfolio weights estimator shows that the portfolio problem in this case reduces to a...

I investigate a dynamic life-cycle strategic asset allocation and consumption problem under model uncertainty, where both inflation rate and income growth rate are assumed to be estimated with errors. I present a feasible boundary for the uncertainty aversion parameter, which measures the...

We consider an investor who faces parameter uncertainty in a continuous-time financial market. We model the investor's preference by a power utility function leading to constant relative risk aversion. We show that the loss in expected utility is large when using a simple plug-in strategy for...

I investigate a dynamic life-cycle strategic asset allocation and consumption problem under model uncertainty, where both inflation rate and income growth rate are assumed to be estimated with errors. I present a feasible boundary for the uncertainty aversion parameter, which measures the...

This paper studies the relationship between mutual fund manager investment horizons and managerial risk-taking decisions. I find that in general mutual funds reporting longer maximum evaluation horizons have lower risk levels. The low risk levels helped these funds mitigate their losses in the...

Consider using the simple moving average (MA) rule of Gartley (1935) to determine when to buy stocks, and when to sell them and switch to the risk-free rate. In comparison, how might the performance be affected if the frequency is changed to the use of MA calculations? The empirical results show...