Ex Ante Bond Returns and the Liquidity Preference Hypothesis
用非参数方法检验流动性偏好假说（即事前期限溢价单调性），发现点估计虽与文献中违反假说的结论一致，但统计上不显著，说明需正确考虑跨期限相关性并正式检验不等式约束。
We provide a formal test of the liquidity preference hypothesis (LPH), that is, the monotonicity of ex ante term premiums, using nonparametric estimates that do not require a structural model for conditional expected returns. Although the point estimates of the term premiums are consistent with previous conclusions in the literature regarding violations of the LPH, the test statistics are generally insignificant, even when powerful conditioning information is used. These results illustrate the importance of correctly accounting for correlations across maturities and of formally testing the inequality restrictions implied by the LPH.