Dear all,
I am trying to estimate a fertility curve, using the data in the attached workfile.
I am trying to estimate the following equation using least squares (other estimation methods also do not yield results).
equation eq1.ls fertility=c(1)*(c(2)/c(3))*(c(3)/age)^(3/2)*exp((c(2))^2*(c(3)/age+age/c(3)2))
I keep getting an error message saying I have insufficient observations, which I don't understand. Any assistance would be greatly appreciated.
Insufficient observations
Moderators: EViews Gareth, EViews Moderator
Insufficient observations
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 Fertility_eviews.WF1
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 Nonnormality and collinearity are NOT problems!
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Re: Insufficient observations
EViews starts estimation with whatever is stored in the c vector. In your case, this is causing some division by zero. Try saying
before you start the estimation.
Code: Select all
c = 1
Re: Insufficient observations
startz wrote:EViews starts estimation with whatever is stored in the c vector. In your case, this is causing some division by zero. Try sayingbefore you start the estimation.Code: Select all
c = 1
Many thanks Startz, works perfectly.
Re: Insufficient observations
Dear all,
I've encountered the same issue, so your answer was very useful  many thanks for that.
Based on the workfile attached in this thread, I have a question concerning the starting point values. I have set the following equation and starting point values, which should be close enough to the actual curve:
param c(1) 1 c(2) .15 c(3) 30 c(4) 8
equation eq1.ls fertility=2*c(4)^(1)*exp((agec(3))/c(4))/((1+exp((agec(3))/c(4)))^2*(1+exp(c(1)*((agec(3))/c(4))c(2)*((agec(3))/c(4))^3)))
However, when I change these values, I do not get any changes in the estimated coefficients (which I would expected). Also, even if I close and open the program, I get convergence all the time in the same number of iterations. I wouldn't have expected this maybe I'm thinking in terms of the "Solver" addin of Excel, and that's confusing me (relatedly, the estimation I get through Solver by minimizing the SSR is much closer to the actual figure compared to what I get in Eviews).
Any help would be highly appreciated.
Thanks in advance.
I've encountered the same issue, so your answer was very useful  many thanks for that.
Based on the workfile attached in this thread, I have a question concerning the starting point values. I have set the following equation and starting point values, which should be close enough to the actual curve:
param c(1) 1 c(2) .15 c(3) 30 c(4) 8
equation eq1.ls fertility=2*c(4)^(1)*exp((agec(3))/c(4))/((1+exp((agec(3))/c(4)))^2*(1+exp(c(1)*((agec(3))/c(4))c(2)*((agec(3))/c(4))^3)))
However, when I change these values, I do not get any changes in the estimated coefficients (which I would expected). Also, even if I close and open the program, I get convergence all the time in the same number of iterations. I wouldn't have expected this maybe I'm thinking in terms of the "Solver" addin of Excel, and that's confusing me (relatedly, the estimation I get through Solver by minimizing the SSR is much closer to the actual figure compared to what I get in Eviews).
Any help would be highly appreciated.
Thanks in advance.
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