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Hi everyone,

I am regressing panel data, and I keep getting the error message near singular matrix when I change the Period function to fixed and I get the error message 'positive or non-negative argument to function estimate expected of RE innovation variance' when I change it to random.

Can someone please explain what this means in laymans terms and how I can hope to correct it?

I've removed variables to deal with collinearity, but no matter how many i remove, I still get these error signs.

PLEASEPLEASE help me!! I'm stuck and am losing hope as I am not really sure what I am doing

Could you post your workfile, and tell us the exact specification you're using?

I am trying to regress log(gdp) on log(airtransport) log(container port) log(electricity power loss) log(ICT imports) log(infant mortality) log(improved water source) log(raillines) (log road network) log(school enrolment) and Log(mortaility rates).

I have 57 cross sections spanning 1990-2009

I recognise that there are lots of variables and so I cut them, but regardless of which ones I cut out, or even if I just estimate using one dependent variable, it still gives me those error messages.

Am I missing something?

It would be much easier to track down what you've done if you posted and EViews workfile, including the equation you are trying to estimate.

Sorry I am new to this.

In an ideal world, I would like to estimate:

log(gdp)= log(elecloss) log(airfreight) log(ictimport) log(infmort) log(mobile) log(port) log(railtot) log(roadtot) log(secondsch) log(water)

In panel options, it's not letting me change for fixed/random effect for the period.

I have never worked with panel data before so I could be missing something glaringly obvious and stupid!

Your dependent variable (GDP) has no cross-section variance. i.e. it is the same for all cross-sections. You can't use the panel options if that's the case.

In what sense is it the same as I have (hopefully) got a different GDP value for each corresponding year for each country?

Your values for electric power are the same for every country, at least for 1990 and 1991. Therefore you can't estimate a period fixed effect.

Most likely, you have a data error.

Sorry for being such a novice at these things! I am trying to teach myself and it is not going so well.

In what sense is it the same as I have (hopefully) got a different GDP value for each corresponding year for each country?

Take a look at the values for GDP in 1990 for cross-section 1. It is identical for GDP in 1990 for cross-section 2, and cross-section 3 etc....

As Startz pointed out, you have data errors.

I think that is working now- I knew it was something stupid on my part.

Thank you so much for your help I really appreciate it and I am sorry if I bother you with more silly questions!