Testing for Unit roots Consider an AR(1): y=a+p +e,t Let Ho: p=1, (assume there is a unit root) Define 0=p-1 and subtract y, from both sides to obtain Ay,=a+ B+e, Unfortunately, a simple t-test is inappropriate, since this is an I(1) process ADickey-Fuller Test uses the t-statistic, but different critical values Economics 20- Prof anderson

▪ 10.1 时间序列分解 ▪ 10.2 长期趋势分析 ▪ 10.3 季节变动分析 ▪ 10.4 循环波动分析 ▪ 10.5 时间序列的自相关分析 ▪ 10.6 时间序列的动态分析指标 ▪ 10.7 景气循环分析

Choosing a Topic Start with a general area or set of questions Make sure you are interested in the topic Use on-line services such as EconLit to investigate past work on this topic Narrow down your topic to a specific question or issue to be investigated Work through the theoretical issue Economics 20-Prof. Anderson

多重反应的收率及选择性 多重反应包括:同时反应,平行反应,连串反应,平行连串反应 1.同时反应:反应系统中同时进行两个或两个以上的反应物与产物 都不相同的反应:如:

Binary dependent variables Recall the linear probability model, which can be written as P(=1x)=Bo+xB a drawback to the linear probability model is that predicted values are not constrained to be between 0 and An alternative is to model the proba、,s a function, G(Bo+xB), where 0