Factor Neutrality
研究了强制保持因子中性对投资组合信息比率的影响，发现尤其在股票数量有限时，因子中性会导致信息比率显著下降，甚至可能不是最优策略。
Investors have views on both factor returns and stock-specific returns, and the results they achieve may reflect both return components to varying degrees. Attempting to eliminate the impact of a particular factor may not be desirable. Application of an analytical framework to consider the potential deterioration in investment performance suggests a substantial loss in information ratio due to enforcement of factor neutrality, particularly with a limited number of stocks in a portfolio, as is often the case in the real world. The IR may be affected even if all information available is on stock-specific returns, when different universes are used to estimate the factor structure and to construct the portfolio. Maintaining factor neutrality can be suboptimal.