Conducting inference in semiparametric duration models under inequality restrictions on the shape of the hazard implied by job search theory
扩展了半参数风险模型，加入风险函数形状的不等式约束，仅用持续时间数据检验求职理论关于风险形状的假设，为失业持续期的理论与实证研究建立新联系。
Using a four-month panel of revised Current Population Survey data from September–December 1993, we extend the class of semiparametric hazard models of the type first studied by Prentice and Gloeckler (1978), and brought to the attention of economists by Meyer (1988, 1990), to incorporate inequality restrictions on the shape of the hazard. This extension enables us to test hypotheses regarding the shape of the hazard implied by search theory using duration data alone. These tests provide another link between the empirical and theoretical literatures on unemployment duration and job search. The GHK probability simulator makes it straightforward to generate approximate hypothesis test results, as simulation estimates of the probability under the null hypothesis are generated using the asymptotic normal approximation to the distribution of the hazard parameters obtained from maximum likelihood estimation. Importance sampling is used to conduct inference under the null and obtain exact finite sample estimates of the probability the null is satisfied. A new algorithm for maintaining stability of the importance weights is also developed. Copyright © 1999 John Wiley & Sons, Ltd.