BBAuthors: Nguyễn, Thế Hòa; Advisor: -; Participants: - (2009)
Determining a demand function or a import demand function is one of the basic and meaningful studies in economics, since it may be used for many economic purposes such as forecasting quantity demanded for following time periods, assessment of effects of government policies on social welfair changes, especially taxation, and others. To do so, one must use multiple regression analysis in econometrics. In this process one has to cope with the unit root problem. But much of time series have unit roots (nonstationary series). That means it can lead spurious results and a relationship between the variables of the model in fact none exists. With traditional approach of Johansen method, one h... 
