Data ready to be used

[Sahara]

I would like to know how to know that my data is good or ready to be used on a research. If I have an excel file with all the data and plot it on eviews, is it good to be used? Is there a way to be sure before continuing with my research?

Thank you for your time!

[trubador]

I think you are asking for preliminary data analysis, which depends on the nature and the purpose of your research. EViews has many diagnostic tools that can guide you throughout your research. However, you can never be 100% sure about the quality or feasibility of your data before digging into it.

[Sahara]

I need to perform a johansen cointegration test. Therefore, I need to test for the unit root of series of Bonds. I have performed the ADF and all 6 series are considered to be non-stationary. However, when I perform at 1st difference, it seems to be stationary. My question is: I am able to use this data to perform the johansen cointegration test?
If the answer is indeed positive, do I have to save this results at 1st difference to use with the johansen test or can I just use select the johansen option and analyse the results? I hope I am being clear with my questions =/

[Sahara]

In order to be more clear regarding my question about saving the 1st differencing series.
Can I do the command GENR "dGER = d(GER) ", " dES = s(ES) " and then use this new series to conduct my research on Johansen and Granger tests? Or do I use the previous series GER and ES? This might be a really silly question but it would help me to know the answer

[trubador]

You can use your data in levels, without the need to take differences.

[Sahara]

Thank you for the tip!

Will the results for granger and johansen be different if I use the 1st difference level? If so, which one do you advice to use, the 1st difference or the levels?