Francisco Barillas

Doubts or variability

Reinterpreting most of the market price of risk as a price of model uncertainty eradicates a link between asset prices and measures of the welfare costs of aggregate fluctuations that was proposed by Hansen, Sargent, and Tallarini [17], Tallarini [30], Alvarez and Jermann [1]. Prices of model uncertainty contain information about the benefits of removing model uncertainty, not the consumption fluctuations that Lucas [22] and [23] studied. A max-min expected utility theory lets us reinterpret Tallarinis risk-aversion parameter as measuring a representative consumers doubts about the model specification. We use model detection instead of risk-aversion experiments to calibrate that parameter. Plausible values of detection error probabilities give prices of model uncertainty that approach the Hansen and Jagannathan [11] bounds. Fixed detection error probabilities give rise to virtually identical asset prices as well as virtually identical costs of model uncertainty for Tallarinis two models of consumption growth.

Comparing Asset Pricing Models

A Bayesian asset-pricing test is derived that is easily computed in closed-form from the standard F-statistic. Given a set of candidate traded factors, we develop a related test procedure that permits an analysis of model comparison, i.e., the computation of model probabilities for the collection of all possible pricing models that are based on subsets of the given factors. We find that the recent models of Hou, Xue and Zhang (2015a,b) and Fama and French (2015a,b) are both dominated by five and six-factor models that include a momentum factor, along with value and profitability factors that are updated monthly.

Speculation and the Term Structure of Interest Rates

We develop and estimate a tractable equilibrium term structure model populated with rational but heterogeneously informed traders that take on speculative positions to exploit what they perceive to be inaccurate market expectations about future bond prices. The speculative motive is an important driver of trading volume. Yield dynamics due to speculation are (i) statistically distinct from classical term structure components due to risk premia and expectations about future short rates and are orthogonal to public information available to traders in real time and (ii) quantitatively important, accounting for a substantial fraction of the variation of long maturity US bond yields.

Model Comparison with Sharpe Ratios

We show how to conduct asymptotically valid tests of model comparison when the extent of model mispricing is gauged by the squared Sharpe ratio improvement measure. This is equivalent to ranking models on their maximum Sharpe ratios, effectively extending the Gibbons, Ross, and Shanken (1989) test to accommodate the comparison of nonnested models. Mimicking portfolios can be substituted for any nontraded model factors, and estimation error in the portfolio weights is taken into account in the statistical inference. A variant of the Fama and French (2018) 6-factor model, with a monthly updated version of the usual value spread, emerges as the dominant model.

Changing Beliefs About the Macroeconomy and Asset Prices

This paper examines an equilibrium asset pricing model with Epstein-Zin preferences in which the beliefs about the fundamentals in the Macroeconomy are time varying. A vector autoregression with time varying parameters and stochastic volatilities of consumption growth and inflation is estimated using an MCMC algorithm. The model generates time-varying countercyclical market prices of risk and is able to match broad movements in short and long nominal bond yields.