Regression help

[abhinav]

Hi,

I am new to using Eviews. I want to fit my data to an exponential curve: y = a*e^(bx). I am running the regression using two methods:

1. MICE_1= COEF(1)*(EXP(COEF(2)*OBSERVATION))

2. LOG(MICE_1) = COEF(3) + COEF(4)*OBSERVATION

Since, both equations are the same, coef(2)=coef(4) and coef(1)= exp(coef(3))

However, I am getting different coefs. using the two equations. Can someone please explain why is this happening?

Thanks,
Abhinav

[startz]

Remember that regression equations include error terms. The error terms here are not the same.

[abhinav]

If I plot my data in excel and go for an exponential trendline, the coefficients of the resulting equation I get match the coefficients I get from this equation: LOG(MICE_1) = COEF(3) + COEF(4)*OBSERVATION

However, I was thinking that the exponential trendline for my data in excel (of the form y = a*e^(bx)) would be same as evaluating MICE_1= COEF(1)*(EXP(COEF(2)*OBSERVATION)) in Eviews. Why is it being evaluated differently in these two software? Any idea?

[startz]

I believe that Excel takes logs.