Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, statalist.org is already up and running.

# st: xtabond problem in results interpretation

 From spyridoula dimou To statalist@hsphsun2.harvard.edu Subject st: xtabond problem in results interpretation Date Mon, 25 Oct 2010 11:10:52 +0100 (BST)

```Goodmorning Statalists!As new in stata i would like your precious help!I want to examine the dynamics in a panel using the Arellano and Bond
methodology. I estimate the impact of ageing (variable called older) to health spending (variable called the)using the above command
-xtabond the older, lags(1)-
and I take this output

Arellano-Bond dynamic panel-data estimation Number of obs = 158
Group variable (i): region Number of groups = 10

Wald chi2(2) = 789.52

Time variable (t): var1 Obs per group: min = 14
avg = 15.8
max = 16

One-step results
------------------------------------------------------------------------------
D.the | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
the |
LD. | .914366 .035845 25.51 0.000 .844111 .9846215
older |
D1. | -.473518 .1784929 -2.65 0.008 -.8233581 -.1236786
_cons | 21.09137 4.829566 4.37 0.000 11.6256 30.55715
------------------------------------------------------------------------------
Sargan test of over-identifying restrictions:
chi2(135) = 163.36 Prob > chi2 = 0.0487

Arellano-Bond test that average autocovariance in residuals of order 1 is 0:
H0: no autocorrelation z = -3.30 Pr > z = 0.0010
Arellano-Bond test that average autocovariance in residuals of order 2 is 0:
H0: no autocorrelation z = -2.35 Pr > z = 0.0190

How can I interpret the results? I have read about the dynamic panel data model in Baum's book but as my stata version is 9 I can't use xtabond2 and follow his example...
I would be really grateful for any help...

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```