Hello,
I am working on two DiD-models in stata, one where the dependent variable is sales, and one where it is the natural logarithm of sales.
I've listed the constant term and DiD-estimator (measuring causal effect of the treatment on sales) below.
constant | DiD | |
ln_sales | 13,5147 | -0,1109463 |
sales | 794 255,80 | -132 841,10 |
I don't understand why the numbers vary. I expected the results to be the same, i.e. that I could convert the ln_numbers by taking the exponential from the first row and get the same result as in the second tow. Here the model suggest two quite different effects of the treatment on sales. The constant terms are not the same either, as exp(13,5147) = 740 217.98, much lower than the constant term in the second model.
Is there a natural explanation to this? Or have I simply done something wrong in the coding?
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