My panel data have these: Number of Companies = 10, Time per Company =9, Number of Independent Variables = 6 I used First Difference GMM with results as follows: *1. Number of instruments =71 while the number of cross-sectional units = 9.* 2. The coefficient of the lag of the DV which is used as an independent variable is less than 1 and statistically significant (p<.001). 3. AR(1) is significant (p<.05) 4. AR(2) is nonsignificant (p>.05) *5. Sargan Test is significant (p<.05)* 6. Wald Test is significant (p<.01). Since #1 and #5 are not OK, then First Difference GMM is inappropriate. I tried the Two-Step Difference and the Systems GMM and all are not OK. Can you suggest an alternative?