Hi,

I am running the following regression:

xtreg recycling loginc logpopden md11 md12 md13 md14 md15 md16 md17 md18 md19 md20 md21 md22 md23 md24 md25 md26 md27 md28 md29 md291 wasteavg dryavg quarter2 quarter3 quarter4 year2 year3 year4 year5, fe vce(cluster acode)

I check for serial correlation using

xtserial recycling loginc logpopden md11 md12 md13 md14 md15 md16 md17 md18 md19 md20 md21 md22 md23 md24 md25 md26 md27 md28 md29 md291 wasteavg dryavg quarter2 quarter3 quarter4 year2 year3 year4 year5, output

This gives me output

Wooldridge test for autocorrelation in panel data
H0: no first-order autocorrelation
F( 1, 310) = 69.989
Prob > F = 0.0000

So I then do

reg D.(recycling loginc logpopden md11 md12 md13 md14 md15 md16 md17 md18 md19 md20 md21 md22 md23 md24 md25 md26 md27 md28 md29 md291 wasteavg dryavg quarter2 quarter3 quarter4 year2 year3 year4 year5)
predict u,resid
regress u l.u
Below is my output.

Source | SS df MS Number of obs = 5,174
-------------+---------------------------------- F(1, 5172) = 703.69
Model | 4128.47295 1 4128.47295 Prob > F = 0.0000
Residual | 30343.7093 5,172 5.86691981 R-squared = 0.1198
-------------+---------------------------------- Adj R-squared = 0.1196
Total | 34472.1822 5,173 6.66386666 Root MSE = 2.4222

------------------------------------------------------------------------------
u | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
u |
L1. | -.3368239 .0126974 -26.53 0.000 -.3617161 -.3119317
|
_cons | -.048475 .0336738 -1.44 0.150 -.1144898 .0175399
------------------------------------------------------------------------------


Am I correct in thinking my results indicate I am inbetween a First difference and Fixed effects estimator?

What commands do I need to run this as a first difference calculation? I have never done first difference in Stata before.