This paper uses simulations to evaluate the performance of various methods for estimating factor returns in an approximate factor model when the cross-sectional sample (n) is large relative to the time-series sample (T). We study the performance of the estimators under a variety of alternative...

The foundation of modern portfolio theory is the mean-variance portfolio selection approach of Markowitz (1952, 1959). We discuss the role of factor models in implementing portfolio selection, defining the nature of systematic risk, and estimating the premium for risk bearing

Factor models of security returns decompose the random return on each of a cross-section of assets into pervasive components, affecting almost all assets, and a diversifiable component. We describe four alternative approaches to factor models of asset returns. We also discuss issues related to...

An important issue in applications of multifactor models of asset returns is the appropriate number of factors. Most extant tests for the number of factors are valid only for strict factor models, in which diversifiable returns are uncorrelated across assets. In this paper we develop a test...

This paper develops a dynamic approximate factor model in which returns are time-series heteroskedastic. The heteroskedasticity has three components: a factor-related component, a common asset-specific component, and a purely asset-specific component. We develop a new multivariate GARCH model...

Two-pass cross sectional regression (TPCSR) is frequently used in estimating factor risk premiums. Recent papers argue that the common practice of grouping assets into portfolios to reduce the errors-in-variables (EIV) problem leads to loss of efficiency and masks potential deviations from asset...

We evaluate the performance of various methods for estimating factor returns in an approximate factor model. Differences across estimators are most pronounced when there is cross-sectional heteroskedasticity, or when cross-sectional sample sizes, n, are below 4,000 assets. Estimators...

This paper considers two methods of estimating factor mimicking portfolios from asset returns: Two-pass cross-sectional regression and asymptotic principal components. We show that, for a balanced panel of assets, iterating the two-pass cross-sectional regression converges to the same estimated...