This paper provides an estimation procedure for average treatment effect through a random coefficient dummy endogenous variable model. A leading example of the model is estimating the effect of a training program on e...This paper provides an estimation procedure for average treatment effect through a random coefficient dummy endogenous variable model. A leading example of the model is estimating the effect of a training program on earnings. The model is composed of two equations:an outcome equation and a decision equation.Given the linear restriction in outcome and decision equations,Chen(1999) provided a distribution-free estimation procedure under conditional symmetric error distributions. In this paper we extend Chen's estimator by relaxing the linear index into a nonparametric function,which greatly reduces the risk of model misspecification. A two-step approach is proposed:the first step uses a nonparametric regression estimator for the decision variable,and the second step uses an instrumental variables approach to estimate average treatment effect in the outcome equation. The proposed estimator is shown to be consistent and asymptotically normally distributed. Furthermore,we investigate the finite performance of our estimator by a Monte Carlo study and also use our estimator to study the return of college education in different periods of China. The estimates seem more reasonable than those of other commonly used estimators.展开更多
Objective: To observe the clinical efficacy of Gao's nape acupuncture plus swallowing training in treating pharyngeal deglutition disorder after stroke. Methods: One hundred patients with post-stroke pharyngeal de...Objective: To observe the clinical efficacy of Gao's nape acupuncture plus swallowing training in treating pharyngeal deglutition disorder after stroke. Methods: One hundred patients with post-stroke pharyngeal deglutition disorder were randomized into a treatment group and a control group, with 50 cases in each group. The two groups both received routine neurological intervention. In addition, the treatment group was given Gao's nape acupuncture plus swallowing training, while the control group was intervened by swallowing training alone. After eight-week treatment, the two groups were observed in terms of the changes in repetitive saliva swallowing test (RSST), modified water swallowing test (MWST), standardized swallowing assessment (SSA) and swallowing-related quality of life (SWAL-QOL). The clinical efficacies of the two groups were also compared. Results: After treatment, the RSST grading, and scores of MWST, SSA and SWAL-QOL changed significantly in both groups (P<0.05 or P<0.01). The RSST grading, and scores of MWSX SSA and SWAL-QOL in the treatment group were significantly different from those in the control group after treatment (P<0.05 or P<0.01). The total effective rate and markedly effective rate were respectively 100.0% and 72.3% in the treatment group, versus 97.9% and 34.0% in the control group. There was a significant differenee in the markedly effective rate between the two groups (P<0.01). The differenee in the clinical efficacy between the two groups was statistically significant (P<0.01). Con elusion: Gao's n ape acupu ncture plus swallowi ng training is an effective approach for post-stroke phary ngeal deglutiti on disorder. Its therapeutic efficacy is more significant than that of swallowing training alone.展开更多
基金supported by National Natural Science Foundation of China(GrantNo.71171127)the Construction Program of Elaborate Course for Advanced Econometrics Ⅱ of ShanghaiUniversity of Finance and Economics
文摘This paper provides an estimation procedure for average treatment effect through a random coefficient dummy endogenous variable model. A leading example of the model is estimating the effect of a training program on earnings. The model is composed of two equations:an outcome equation and a decision equation.Given the linear restriction in outcome and decision equations,Chen(1999) provided a distribution-free estimation procedure under conditional symmetric error distributions. In this paper we extend Chen's estimator by relaxing the linear index into a nonparametric function,which greatly reduces the risk of model misspecification. A two-step approach is proposed:the first step uses a nonparametric regression estimator for the decision variable,and the second step uses an instrumental variables approach to estimate average treatment effect in the outcome equation. The proposed estimator is shown to be consistent and asymptotically normally distributed. Furthermore,we investigate the finite performance of our estimator by a Monte Carlo study and also use our estimator to study the return of college education in different periods of China. The estimates seem more reasonable than those of other commonly used estimators.
文摘Objective: To observe the clinical efficacy of Gao's nape acupuncture plus swallowing training in treating pharyngeal deglutition disorder after stroke. Methods: One hundred patients with post-stroke pharyngeal deglutition disorder were randomized into a treatment group and a control group, with 50 cases in each group. The two groups both received routine neurological intervention. In addition, the treatment group was given Gao's nape acupuncture plus swallowing training, while the control group was intervened by swallowing training alone. After eight-week treatment, the two groups were observed in terms of the changes in repetitive saliva swallowing test (RSST), modified water swallowing test (MWST), standardized swallowing assessment (SSA) and swallowing-related quality of life (SWAL-QOL). The clinical efficacies of the two groups were also compared. Results: After treatment, the RSST grading, and scores of MWST, SSA and SWAL-QOL changed significantly in both groups (P<0.05 or P<0.01). The RSST grading, and scores of MWSX SSA and SWAL-QOL in the treatment group were significantly different from those in the control group after treatment (P<0.05 or P<0.01). The total effective rate and markedly effective rate were respectively 100.0% and 72.3% in the treatment group, versus 97.9% and 34.0% in the control group. There was a significant differenee in the markedly effective rate between the two groups (P<0.01). The differenee in the clinical efficacy between the two groups was statistically significant (P<0.01). Con elusion: Gao's n ape acupu ncture plus swallowi ng training is an effective approach for post-stroke phary ngeal deglutiti on disorder. Its therapeutic efficacy is more significant than that of swallowing training alone.
