开发者:上海品职教育科技有限公司 隐私政策详情

应用版本:4.2.11(IOS)|3.2.5(安卓)APP下载

wenxing · 2023年02月11日

求解析

* 问题详情,请 查看题干

NO.PZ202208300200000104

问题如下:

Assuming a 5% level of significance, the most appropriate conclusion that can be drawn from the Dickey–Fuller results reported in Exhibit 2 is that the:

选项:

A.test for a unit root is inconclusive for the dependent variable.

B.dependent variable exhibits a unit root but the independent variables do not.

C.independent variables exhibit unit roots but the dependent variable does not.

解释:

The Dickey–Fuller test uses a regression of the type:xt-xt-1 =b0+g xt-1+εt

The null hypothesis is H0: g= 0 versus the alternative hypothesis H1: g< 0 (a one-tail test). If g=0 the time series has a unit root and is nonstationary. Thus, if we fail to reject the null hypothesis, we accept the possibility that the time series has a unit root and is nonstationary. Based on the t ratios and their significance levels in Exhibit 2, we reject the null hypothesis that the coefficient is zero for both outside air temperature and assembly line speed (i.e., the independent variables). We do not reject the null for the dependent variable, defective assemblies per hour.

求解析!!!,!!!!!!!!!!!!!!

1 个答案

星星_品职助教 · 2023年02月12日

同学你好,

这道题有些超纲,DF test的具体做法教材没讲也不要求掌握。但原则依然是当p-value<significance level时,拒绝原假设。(significance of t就是p-value的同义表达)。

由此可以看出,两个X的p-value都小于5%(拒绝g=0的原假设,即covariance stationary),但Y的p-value大于5%(不能拒绝原假设,不满足covariance stationary,存在unit root)。

  • 1

    回答
  • 0

    关注
  • 640

    浏览
相关问题

NO.PZ202208300200000104问题如下 Assuming a 5% level of significance, the most appropriate conclusionthcawn from the ckey–Fuller results reportein Exhibit 2 is thatthe: A.test for a unit root is inconclusive for the penntvariable.B.pennt variable exhibits a unit root but theinpennt variables not.C.inpennt variables exhibitunit roots but the pennt variable es not. The ckey–Fuller test uses a regression of the type:xt-xt-1=b0+g xt-1+εt The null hypothesis is H0: g= 0 versus the alternativehypothesis H1: g 0 (a one-tail test). If g=0 the time series hasa unit root anis nonstationary. Thus, if we fail to rejethe nullhypothesis, we accept the possibility ththe time series ha unit root ans nonstationary. Baseon the t ratios antheir significanlevels inExhibit 2, we rejethe null hypothesis ththe coefficient is zero for bothoutsi air temperature anassembly line spee(i.e., the inpenntvariables). We not rejethe null for the pennt variable, fectiveassemblies per hour. 表格中的数字怎么和题目对应起来?完全不知道怎么用

2024-05-24 07:26 1 · 回答

NO.PZ202208300200000104 问题如下 Assuming a 5% level of significance, the most appropriate conclusionthcawn from the ckey–Fuller results reportein Exhibit is thatthe: A.test for a unit root is inconclusive for the penntvariable. B.pennt variable exhibits a unit root but theinpennt variables not. C.inpennt variables exhibitunit roots but the pennt variable es not. The ckey–Fuller test uses a regression of the type:xt-xt-1=b0+g xt-1+εt The null hypothesis is H0: g= 0 versus the alternativehypothesis H1: g 0 (a one-tail test). If g=0 the time series hasa unit root anis nonstationary. Thus, if we fail to rejethe nullhypothesis, we accept the possibility ththe time series ha unit root ans nonstationary. Baseon the t ratios antheir significanlevels inExhibit 2, we rejethe null hypothesis ththe coefficient is zero for bothoutsi air temperature anassembly line spee(i.e., the inpenntvariables). We not rejethe null for the pennt variable, fectiveassemblies per hour. 我知道 test是从AR(1) mol xt-xt-1 =b0+g xt-1+εt开始,但还是不太懂该怎么解题,我的疑问如下,谢谢!这题pennt variable (fective assemblies per hour) 和 inpennt variables (outsi air temperature anassembly line spee 该怎么写成mol的形式?关于检验inpennt varibale有无unit root,我的做法对吗?【H0是假设g=0。如果g=0,那就有unit root。outsi air temperature 和 assembly line spee统计量分别是-5.846 和 -13.510,都是落在±1.96之外,所以要拒绝H0,说明两个inpennt variables没有unit root。】pennt variable怎么检验有无unit root? 检验里面的变量都是现在的X和过去的X。

2022-11-30 20:35 1 · 回答